Final Report 402

EVALUATION OF HEAVY METAL
CONCENTRATIONS IN CANNED TUNA FISH SOLD IN
LAE CITY SUPERMARKET
A DISSERTATION
Submitted by
JOYCE MICHAEL
SUPERVISOR: MR. NARIMBI
In Partial Fulfillment of the Requirements for the
DEGREE OF BACHELOR OF SCIENCE
APPLIED CHEMISTRY SECTION
DEPARTMENT OF APPLIED SCIENCES
THE PAPUA NEW GUINEA UNIVERSITY OF TECHNOLOGY
SEPTEMBER 2016

i
Acknowledgement
I would like to acknowledge the following hard working people who helped me carry out this
research.
Hazel Hecko (Bachelor of Science in Applied Chemistry Final Year Student)
Isadora Paleu (Bachelor of Science in Food Technology Third Year Student)
Julie Petrus (Bachelor of Science in Agriculture Third Year Student)
KaysiePuringi (Bachelor of Science in Applied Chemistry Final Year Student)
Anna Apio (Bachelor of Science in Applied Chemistry Final Year Student)
Philemon Miul (Post Graduate Applied Physics with Electronics & Instrumentation)
Mr. J Narimbi (Project Supervisor &Environmental Chemistry Lecturer)
Mr. Tata Telawika (UASL Laboratory Manager)
Mr. SoveraGuti (UASL Laboratory Technician)
Dr. Harakuwe (Instrumental Analysis III Lecturer)
These are the people who worked with me until the completion of the research project. Without
them I don’t think the research will be finalized like this in this manner. They helped in terms of
finance, data collection, instrumentation, and other things and therefore I thank them for their
participation and cooperation.

ii
Abstract
Inductively Coupled Plasma Optical Emission Spectrophotometer was used to analyze four
different varieties of canned tuna fish sold in Lae Supermarkets in which two are overseas
products and the other two are PNGs’ manufactured. Dry ashing method was employed in which
1:5 ratio HNO3/HCl reagent was used to bring the metal into solution before further analysis.
The world permissible limit set by EC, WHO and FAO was (0.05-0.5ppm and 0.4-0.5ppm) for
cadmium and lead respectively. The results obtained from the four different canned tuna fish was
found to be (0.0003-0.002ppm) and (0.0001-0.0008ppm) for cadmium and lead respectively
which was much lower than the permissible limit. Many other researchers carrying out similar
research in other countries also reported that the heavy metal content in canned tuna fish are
lower than the permissible limit by Mehdi Zarei et al., (2010), Pourjafar H et al., (2014) and
Mani Mahalakshmi et at., (2011).

iii
Glossary
AAS: Atomic Absorption Spectrometry method that are used for isolating element of interest.
There are all sorts of AAS and they can be used according to the sample type and the element of
interest.
Anthropogenic activities: Human activities that cause environmental pollution
AOAC Method: Association of Official Analytical Chemists method is a book that contains all
the standard laboratory methods that is used world-wide.
Bio-accumulation: The buildup of a substance in a living thing to a concentration that is greater
than the concentration of the substance in the natural environment.
Bio-magnification: Heavy metals concentration in the food chain getting bigger and bigger
from.
Desiccator: A laboratory equipment containing silica gel in it where it is used for cooling very
hot objects within short period of time without contaminating the sample in the object.
FAO: Food and Agricultural Organization
Heavy metal: An element that is poisonous even when present in low concentrations and is
hydrophobic in nature.
Hydrophobic: Hydrophobic elements are metals that do not easily react with water hence tend
to form emulsified solution. Hydrophilic is the opposite to hydrophobic where they easily react
with water.
ICP-OES: Inductively Coupled Plasma- Optical Emission Spectroscopy is a type of
spectrometry method that uses plasma for isolation of element of interest.
Leaching: Is the action of bringing the solid sample into solution using an appropriate leaching
agent

iv
Lixiviant: A reagent that is either a base or an acid that is used for extraction of element of
interest in a sample.
Muffle Furnace: A heating equipment used for drying and ashing samples at different
temperature ranges according to a standard procedure you applied to get samples dried or ashed.
Non-point source: Many sources of pollution those are non-identifiable.
Point source: Only one source of pollution that is identifiable
Reagent: Any upgraded acids and bases that are recommended for usage in the laboratory to
digest, titrate, and to analyze samples. Different samples uses different reagent according to the
AOAC standard method.
Sampling: Is the action of taking out a portion of something for analyses purpose.
WHO: World Health Organization.

v
Table of Contents
Acknowledgement ...................................................................................................................................i
Abstract...................................................................................................................................................... ii
Glossary .................................................................................................................................................... iii
CHAPTER ONE: INTRODUCTION .......................................................................................................1
1.1: Background ..................................................................................................................................1
1.1.1: Heavy metals in the global contexts ..............................................................................3
1.1.2. Heavy metals in PNG local contents..............................................................................4
1.2: Research Problem ......................................................................................................................5
1.3: Study Location .............................................................................................................................5
Figure 1.1: Map of PNG showing the highlighted Morobe Province......................................6
1.4: Research aim and specific objectives ..................................................................................6
1.5: Research hypothesis..................................................................................................................6
1.6: Significance of the study...........................................................................................................7
1.7. Outcomes and Benefits .............................................................................................................7
1.8: Thesis Outline...............................................................................................................................7
CHAPTER TWO: BACKGROUND ........................................................................................................9
2.1: Introduction ..................................................................................................................................9
2.2. Literature Review......................................................................................................................10
2.3: Physical, geographical, and socio-economic description of the study environment
................................................................................................................................................................14
2.4: Detailed discussion of Heavy metals...................................................................................15
2.4.1 Causes and Effects of heavy metals in the body .......................................................16
2.4.2. Lead.......................................................................................................................................16
2.4.3. Cadmium ..............................................................................................................................17
CHAPTER THREE: METHODOLOGY................................................................................................19
3.1. Introduction ................................................................................................................................19
3.2: Method of Application..............................................................................................................19
3.2.1: Dry ashing method ............................................................................................................19
3.2.2: Purpose of method............................................................................................................20
3.2.3: Scope or field of application...........................................................................................20
3.3: Reagents......................................................................................................................................20

vi
3.3.1: Standards for ICP-OES ....................................................................................................21
Figure 3: Standard formula for calculating the unknown concentration and volume.......21
3.4.1: Procedures:.........................................................................................................................21
3.5: Sampling......................................................................................................................................22
Figure 3.2: Sample Preparation Chart..........................................................................................23
3.5.1: Dry-ashing Method ............................................................................................................23
Figure 3.3: Ratio of reagent used for sample preparation......................................................24
Figure 3.4: General view of how Inductively Coupled Plasma-Optical Emission
Spectrophotometer (ICP-OES) normally work............................................................................25
3.7: Analytical quality assurance and control...........................................................................25
3.8: Data processing and analyses ..............................................................................................26
CHAPTER FOUR: RESULTS ...............................................................................................................27
4.1: Introduction ................................................................................................................................27
4.2: Results..........................................................................................................................................27
Table 4.1: Table showing results obtained from ICP-OES.......................................................27
4.3: Data analysis and statistical evaluation .............................................................................27
CHAPTER FIVE: DISCUSSION...........................................................................................................30
CHAPTER SIX: CONCLUSIONANDRECOMMENDATION ...........................................................31
6.1: Conclusion...................................................................................................................................31
6.2. Recommendations....................................................................................................................31
REFERENCES.........................................................................................................................................32
APPENDICES..........................................................................................................................................34
APPENDIX A: A MAP SHOWING MOROBE PROVINCE IN PAPUA NEW GUINEA...................34
APPENDIX B: SHOWING HOW THE SAMPLE PREPARATION WAS DONE ...............................34
APPENDIX C: SHOWING HOW THE ICP-OES WORKS..................................................................35

1
CHAPTER ONE: INTRODUCTION
1.1: Background
Heavy metals are naturally occurring elements that have high atomic weight and high density
that is of at least five times greater than that of the density of water (Tchounwou.et al., 2014).
There are multiple industrial, domestic, agricultural, medical and technological applications that
primarily aid to distribute heavy metals that destroy the natural environment. Government and
other concern citizen of this nation are raising concerns over the potential effects of heavy metals
in human’s life. The toxicity of these metals depends on several factors including the dose, route
of exposure and their chemical species (Janarthanan, 2014). Because of their high degree of
toxicity in the body, cadmium, lead, mercury, arsenic and chromium rank among the priority
metals that are of public health significance. These are the primary elements that make up the
Earth’s crust and cannot be naturally broken down into further simpler substances(Ahmed Q
&BatL, 2015)
Initially heavy metals naturally occur in the environment with other primary elements to create
new things and to sustain life on earth (Ahmed Q &BatL, 2015). It is via the natural and
anthropogenic activities that pollute the environment so badly that directly poison the living
tissue of an organism’s body system(AN. Sabramanian., 2009). Pollutants enter the aquatic
environment from two main types of sources. The anthropogenic activities which drastically
affect the environment are classified into point and non-point sources of pollution. Point source
pollution is a type of pollution that people can easily identify its origin. It is a single source for
example a sewage treatment or industrial tailings discarded into rivers or sea (Point Sources of
Pollution, n.d.) whereas a non-point sources of pollution refers to the type of pollution that is
caused by a combination of sources where it is non-identifiable. An example of a point source
pollution include pipe or a drain where industrial wastes are commonly discharged into the rivers
and seas (EPAV) whilst a non-point source is defined to mean any source of water pollution that
does not meet the legal definition of point sources like fog and smog (Non-point Sources of
Pollution, n.d.). Due to the above activities the water body became unhealthy for aquatic and
marine species to breed and reproduce easily.

2
All edible substances on earth can become toxic to human body if their concentration is way
beyond the permissible limit. A few of these elements are poisonous even if present in a very low
concentration like cadmium which is very toxic at 0.05-0.5 ppm and lead at 0.4-0.5 ppm. These
are known as heavy metals. Examples of heavy metals include mercury (Hg), cadmium (Cd),
lead (Pb) arsenic (As), chromium (Cr), thallium (Tl), and aluminum (Al) (Lenntech, B.V., 2016).
Some of the heavy metals are considered essential to the body system like zinc (Zn), magnesium
(Mg), potassium (K), sodium (Na) and calcium (Ca). However, trace minerals including
selenium, iodine, boron and molybdenum became poisonous when present in excessive amount
in the body. For example zinc ion in the body can be easily replaced by the cadmium ion in the
DNA and RNA synthesis and can directly change the function of the enzyme in the body leading
to so many related body mal-functioning and diseases (Heavy Metal., 2016)
It is via natural and anthropogenic activities that aid to contribute more of the heavy metals onto
the aquatic environment (Lenntech, BV, 2016). Weathering processes easily brings and deposits
most of the heavy metals, pollutants, toxicants and hazardous substances into the open dynamic
system from their primary and secondary deposits (Pooter, 2013). Since the heavy metals are
quite dense they are able to sink into the ocean floor where the sediments are (Pooter, 2013). The
properties of metals dissolved in water depend largely upon the nature of metal species dissolved
in the water. Therefore, speciation of metals plays a crucial role in their environmental chemistry
in natural waters and wastewaters (Manahan, 2000).Most fishing industries use the large sizes
fish for fish products and when people consume most marine products it is assumed that they
tend to ingest higher doses of heavy metals of relatively high content depending on daily, weekly
and monthly intakes. Fish products are sold in bulk quantities compared to other fishmeal and the
demand is very high depending on those products daily consumed without paying close attention
to its side effects. It is primarily believed that the concentration of heavy metals in canned tuna
depends on the;
1. Sizes of raw fish (very large)
2. Life span (15-30 years)

3
3. Distance travelled by tuna (44-62m/h)(Tuna Facts, 2016)
Due to the unique characteristics of tuna fish that draws the attention of researches to do more
research regarding heavy metal and the facts listed below have been abstracted out of the tuna
facts (Tuna Facts, 2016);
 Larger in sizes
 Tunas can travel large distances in a short period of time. It can pass across entire
Atlantic in 30 days by traveling 16 miles per hours
 Despite their large size, tunas are very fast swimmers. They can reach the speed between
44 and 62 miles per hour.
 Average life span of tuna is between 15 and 30 years in the wild. Small percent of tuna
managed to survive until this period.
 Tuna can swim near the surface or can dive to the depth of 3000 feet while it searches for
food.
 Tuna is a carnivore. It feeds on different types of fish (mackerel, herring, hake…), squids
and crustaceans.
This work is limited in its scope in that it only looks atonlyfour different types of canned tuna
fish commonly sold and consumed. Two products analyzed are manufactured from Indonesia
and Thailand while two are PNG manufactured.Unfortunately not all tuna products soldin Lae
supermarkets are analyzed. This is largely due to limiting factors such as time, finance and
analytical instrumentation.
1.1.1: Heavy metals in the global contexts
Tunas are usually located in temperate and sub-tropical waters of Atlantic Ocean, Mediterranean
and Black seas. Tunas are over-fished in different parts of the world, especially in Japan and
Australia (Tuna Facts, 2016). Due to large population and so many industries all across the globe
anthropogenic activities tend to contribute more pollutants into the natural environment. It

4
directly pollutes the natural environment and alters its physical, biological, and chemical
properties of the natural system. “The sources of metal pollution come from manufacturing,
agriculture, sewerage treatment, industries, motor vehicle emissions, logging and mining
industrial sites” (Shazili, et, at 2007) .
The world outside is so industrialized and more developed where they emit and discharge so
many hazardous chemical as waste into the air and sea compared to PNG as one of the
developing country with little industrial activities, logging, agricultural farming, vehicle
emissions and sewage treatment. The leading infrastructural development in the world was Hong
Kong followed by Singapore and list continues. PNG doesn’t appear in the world statistical data
with respect to infrastructural development which signifies that PNG is the last with least
infrastructural development (The Statistics Portal, 2015).
1.1.2. Heavy metals in PNG local contents
PNG is a small country where there is but not limited to mining industries, agricultural farming
activities, waste sewage treatment, volcanoes and logging companies that pose environmental
pollution.
Purchasing and consumption of our own tuna fish products is much more safer than consuming
tuna fish products from other countries that are sold in Lae supermarkets. Since the outside world
is too industrialized they tend to contribute more pollutants to the sea compared to PNG as
mentioned in the (Statistics Portal, 2015) therefore it can be assumed that their tuna fish products
will contain higher heavy metal concentration than those tuna products produced here in PNG.
People most of the time people don’t consider the quality of the processed seafood but chose
according to the quantity and price to save money and to satisfy hunger. That is the main reason
of purchasing goods and services at the lowest and affordable prices. During the surveying the
researcher saw that tuna products normally ran out of stock faster compared to other canned fish
no matter what classes and type of people purchased the product.
Those canned tuna are of different varieties, processed in different canneries and so it is believed
that it contained different level concentration of heavy metals that is lead and cadmium
specifically that is harmful to the body at very low concentration.

5
1.2: Research Problem
The consumption of fish and fisheries products have led to heavy metals toxicity issues in
humans especially the increased health risks in children and pregnant mothers around the world.
While many studies have been done elsewhere, there is no proper and adequate scientific data
available on the levels of heavy metals in canned tuna products sold and consumed in PNG
(March of Dimes, n.d). Therefore, there exists an urgent need to establish data on this important
issue to fill the missing gap in knowledge. Many health issues affecting mothers and children in
PNG have been linked to poor nutrition. The consumption of canned tuna fish products
containing elevated levels of heavy metals by these age categories could be a potential
confounding factor. Canned tuna fish in particular is an affordable source of protein and is
widely sold in major supermarkets and retail stores in Morobe and easily accessible to the
majority of middle-to-low income settlers in and around Lae city. It is perceived that the
increased consumption of these cheap and affordable canned tuna fish may have some
disadvantages which can easily lead to accumulation of heavy metals that can affect the
biological system of general population.
1.3: Study Location
The study will be conducted in Lae, Morobe Province. Since PNG University of technology is
located within Morobe Province so it is quite easy to conduct sampling within the vicinity of the
city. Furthermore Morobe Province is the second largest city in PNG that consists of so many
industries, schools and private business entities leading to high population. In such place that
caters so many people, their health and environment must be governed and protected. For this
reason the researcher thought it might be helpful to carry out such research here where there are
so many people and high demand for the same product every day. In such place, the possibility
of getting affected by heavy metal related diseases will be very high.

6
Figure 1.1: Map of PNG showing the highlighted Morobe Province
1.4: Research aim and specific objectives
The overall research aim is to establish the cadmium (Cd) and lead (Pb) concentrations of canned
tuna fish sold in Lae supermarket. To achieve the overall aim of this research the following
specific objectives will be implemented.
1. To carry out sampling of canned tuna fish
2. To analyze canned tuna fish for cadmium (Cd) and lead (Pb) concentrations and
3. To evaluate compliance with international acceptable levels for these heavy metals
1.5: Research hypothesis
Heavy metal concentrations in canned tuna fish sold in Lae supermarkets is below internationally
permitted standard.
MorobeProvince,
Lae

7
1.6: Significance of the study
This study will highlight the potential risk of heavy metal accumulation by consumers in Lae
city. This information is going to be important for raising awareness to people and encourage
educated decision making in consumer choices. Furthermore, the information generated from
this study will be a useful tool for decision makers and authorities in public health management.
1.7. Outcomes and Benefits
The outcome of the study is to;
 Define heavy metals, their toxicity level, speciation and their health impacts,
 The origin of Cd and Pb pollutants in the environment, their sources of pollution and the
chemical interaction between the pollutant and the environment and the possible impacts
in the life of aquatic biota.
 How the heavy metals especially lead and cadmium enter tuna fish tissue and gets
accumulated.
 How the heavy metals in the canned tuna fish enter human body tissues, gets
accumulated and causes disruption in the enzymatic activities that finally results in health
issues.
 Justify as to why most people favor canned tuna over other brand of canned fish and
 Finally give a clear conclusion on the concentration level of heavy metals in canned tuna
fish in PNG over Thailand, Solomon Island, Indonesia and Fiji.
1.8: Thesis Outline
Chapter one covers the introduction and will include the origin, nature, and sources of heavy
metals present in the environment and cause most of the pollution in the water system. It also
includes the research problem, its significance as to why it is under study, the study location, the

8
objective of the research, the research hypothesis that forms the basis of the study and not
forgetting the outcome of the research that will be accomplished at the end of the research.
Chapter two contains the literature review on heavy metal concentration in canned fish that are
sold worldwide and the toxicity of lead and cadmium in the body whilst chapter three contains
the methodology of the research how the sample will be collected, prepared and the instrument
that will be applied during analysis process. Chapter four will cover the expected results. Chapter
five will discuss the expected results and chapter six will include the conclusion and
recommendation.

9
CHAPTER TWO: BACKGROUND
2.1: Introduction
Fish meat may be contaminated from toxic metals during commercial transport and processing
depending on the raw material before processing occurs. Therefore, monitoring of these products
is important with respect to toxic elements affecting human health (Fathabad, Shariatifar, etal.,
2015). Heavy metals are considered the most important form of pollution of the aquatic
environment because of their toxicity and accumulation by marine organisms.Heavy metals
including arsenic (As), mercury (Hg), lead (Pb) and cadmium (Cd) are hydrophobic in nature and
have the ability to accumulate in the body tissues. On the other hand they have no beneficial
impacts in the body. While other elements such as chromium (Cr), copper (Cu), zinc (Zn), iron
(Fe), manganese (Mn) and other essential micronutrients are essential to the body when present
in lesser concentration but when present in higher concentration also tend to become toxic to the
body(Khansaria,b, Khansaria,*&Albdollahic., 2004).
Metal pollution of the sea is less visible and direct than other types of marine pollution but its
effects on marine ecosystems and humans are intense and very extensive. The toxic effects of
heavy metals, particularly arsenic, mercury, cadmium and lead, have been broadly studied
(Inskip&Piotrowsiki, 1985; Kurieshy&D_siliva, 1993; Narvaes, 2002; Nishihara, Shimamato,
Wen, & Kondo, 1985; Schoerder, 1965; Uchida, Hirakawa, & Inoue, 1961; Venugopal&Luckey,
1975).
Above information proves that there are many researchers carrying out research based on the
same topic. However, their aims and objectives are differently organized. Most cited literature
review collected and written in this research was done outside of the country excluding PNG
which includes Lae, Morobe Province. Therefore the main aim of this research was to determine
the concentrations of heavy metals particularly lead and cadmium in canned tuna fish sold in Lae
supermarkets.

10
2.2. Literature Review
Heavy metals are considered as one of the most important form of pollutants present in the
aquatic environment because of their toxicity and accumulation by marine organisms. The main
exposure by humans to these heavy metals (Cd, and Pb) is via the ingestion of contaminated fish,
especially larger predators including tuna, marlin etc. While mercury, arsenic, cadmium and lead
can be tolerated at extremely low concentrations, they are extremely toxic to humans
(AgyekumAkwasiAkomeah, et al., 2012). Many researchers including both PNG and global had
published their papers by concluding that the natural environment is over polluted that all living
organism in aquatic, marine and terrestrial organism at least contain some heavy metals and it is
also confirmed in (UNADF, 2015, STD Toolkit, 2002, Papua New Guinea Environment
Monitor, 2002 and Quratulan Ahmed &Levent Bat, 2015). “The ingestion of food is an obvious
means of exposure to metals, not only because many metals are natural components of
foodstuffs, but also because of environmental contamination and contamination during
processing” (Voegborlo R.B et al, 1999).
There are many related heavy metal diseases arises recently that needs very close monitoring and
researches have done to prove the possible cause of the diseases. As mentioned earlier cadmium
and lead are very toxic to human in very low concentration and the related diseases that they
caused are very serious in which infants are most vulnerable. The EC, Food and Drug
Authorities (FDA), FAO and the World Health Organization had set the world permissible limit
of cadmium and lead to be (0.05-0.5 & 0.4-0.5ppm). Concentration above this limit can possibly
toxify the body.
Chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), and zinc (Zn), among other metals, are
essential micro-nutrients for humans involved in important biological processes. These elements
prevailingly plays functional and structural role in human body (Rivas, et al 2014). However,
there are no homeostatic mechanisms in the human body to eliminate elements, such as cadmium
(Cd), arsenic (As), mercury (Hg), and lead (Pb) which are classified as heavy metals have no
beneficial functions in human body (Ali-Mutarri 2015). The toxicity of the metals varies and it
also depends mostly on the concentrations at which a specific organism is exposed to. However,
long-term exposure of Hg, As, Cd, and Pb at relatively low levels can have deleterious effects on

11
human health. The European Food Safety Authority (EFSA) has provided evidence that exposure
to these contaminants can cause neurological, cardiovascular and reproductive disorders.
“Metal contamination in an aquatic system is a particular concern because metals are both
persistent and toxic” (Clark 1992). Most environmental pollutants initially came from industrial
waste around the countries and get more concentrated around the estuary and this statement
confirms with Galindo’s research stating that, “The Huelva estuary and the Tinto and Odiel
rivers which flow into it are all affected by discharges from industries and historic mining
activities locally”. The area, in which fishing is forbidden, is globally significant in terms of its
levels of heavy metal contamination. Mining sites may pose a unique risk because metal
concentrations in water at mines tend to be several orders of magnitude higher than those for
uncontaminated sites says Stuart M. Levit. “Metal-contaminated macro-invertebrates are likely
to then form a principal food component in the diet of bottom-dwelling fish, and these fish are
also likely to show increased metal uptake via the gut and directly across the gills. Cumulative
metals, such as cadmium,lead, mercury and arsenic, may be transferred to higher predatory fish
by the processes of bio-magnification.” (STD Toolkit, 2002).
In PNG there are not much anthropogenic activities being practiced compared to other well
industrialized counties. Heavy metal related diseases are more common nowadays. It can be
suspected that canned tuna fish must be a possible cause to it due to its bigger sizes, lived up to
10-30 years, can swim faster regardless of their weights and can even travel 44-62mph searching
for food that is stated in the (Tuna Facts, 2016). All these facts so far collected the researcher can
easily make justifications that tuna fish are eligible to contain more heavy metal than other fish
species. However, many researchers concluded their findings on heavy metal (Pb& Cd)
concentration to be lower than the permissible limit by (Khansari, Ghazi-Khansari&Abdollahi.,
2005 and Al-Mutarri, 2015.)
If the PNG marine environment is heavily polluted by the anthropogenic activities then the
consumer of the final product will be affected as badly as many canned tuna products sold in
Morobe supermarket are PNG made products except only a hand-full of it are of other countries.
However, due to the above reasons the researcher can easily justify by saying that the marine
environment around PNG is somewhat safer to catch tuna fish for production while seas in other

12
countries will be considered unsafe to catch fish for production. This is due to the frequent
application of anthropogenic activities that one way or the other contributes more to the marine
disaster as well as the unique characteristics of tuna fish.
Morobe seas will be safer since it rains a lot and the turbidity of river system and marine will be
able to undergo turbulence where the metals will sometimes form complex with other metals in
the water that cannot be easily broken and in that case some of the complex when consume by
the marine organism cannot be easily broken down by the enzymatic functions in them can easily
remove in the body as a waste. Since there are no literature based on something related to PNG
marine system about pollution free for fishing, this research is the first of its kind to either prove
or disprove the above assigned thesis.
Toxicological and environmental studies have prompted interest in the determination of toxic
elements in food. Cadmium and lead can be tolerated only at extremely low levels and at certain
concentrations they are exceptionally toxic to humans (Voegborlo, 1999).Fish is widely
consumed in many parts of the world because it has high protein content, low saturated fat and
also contains omega fatty acids known to support good health (Ikem and Egiebor, 2005). But
also contain toxic substances hidden in them which are microscopic and cannot be seen with the
negative eyes but can detect through atomic absorption spectrometer (AAS) where very minute
contaminants can be easily detected in parts per million. The distribution of metals varies
between fish species development status and other physiological factors (Kagi and Schaffer,
1998). The effects of these elements on human health have also been widely reported (Lall,
1995; Linder and Hazegh-Azam, 1996; Munoz-Olivas and Camara, 2001).
“China is the world’s number one fish consumer and has the world’s largest fishing industry;
accounting for the third of the world’s catch therefore minamata disease is common in China.
This is followed in order by Peru, Japan, the US, Chile, Indonesia, Russia, India, Thailand,
Norway and Iceland” (Encyclopedia, 2011). However the tuna cans sold in Morobe supermarket
are all imported from Indonesia, Fiji, Thailand and Solomon Island. Hence PNG made products
are also sold in bulk quantities in Morobe compared to Thailand’s, Fijis, Indonesia and Solomon
Island’s manufactures. “Although Peru is number two in the world for catching fish, Peruvians
eat hardly any of this and it is exported. On the other hand, fish is so popular in Japan that

13
although at number two in the catching list, Japan has to buy has much again from other
countries in order to meet the domestic demand” (Encyclopedia, 2011).
Regina Asiad, a representative of the Lihir village planning committee, says that a few years ago,
dugout canoes “overflowing” with fish arrived daily at Lihir’s wharf. “Now you might get five or
six fish in a boat, or absolutely nothing. Strange things happen that we never encountered before.
We find dead fish, and sometimes fish we catch taste strange so people won’t eat it. A lot of pigs
died after eating stuff on the beach. We wonder about that mine.”(Regina A, 2002). If that’s the
case then it is expected to see a lot of deaths occurring in PNG but that doesn’t happened maybe
because this province experiences too much rainfall per annum that can easily have effects on the
aquatic and marine forming oxidation and complexation reaction that the heavy metals from
toxic species to non-toxic species by undergoing the above mentioned reactions. And also tuna
fish are type of fish that travels long distances and by doing so they can be able to move away
from feeding on contaminated small fish. Turbulence arise from the flood can cause pH to
change automatically that can also affect the formation of toxic heavy metal species. Small
creeks around the mine sites where waste sometimes drops in are caught by the ferns on the river
side which help to reduce the concentration of heavy metals before reaching the sea.
Many studies have proved that heavy metals such as lead and cadmium in canned tuna fish have
lots of impacts in human body. Therefore this reason has form the basis of this research that the
researcher tries to identify the particular type of tuna cans accumulates more heavy metals and
which country of manufacturing will possibly cause problems and can find other alternative way
to solve the arising issue rather than being ignorant.
With all these fact analysed above drives researchers to find out the heavy metal concentration in
canned tuna fish and that is why Mehdi Zarei et al., (2010) was carrying out a similar research on
heavy metals in canned tuna fish sold in Iran to see if the five major sold canned tuna fish are the
possible cause of the very severe diseases however they reported that the concentration of
cadmium and lead in the canned tuna fish are (0.002-0.07 μg/g and 0.007-0.51 μg/g)
respectively. The concentration shows that the canned tuna fish sold at Iran are safer for
consumption since the concentrations reported are lower than the permissible limit.

14
There was another similar research type done in 2011 by other Boadi N.O. et al in Ghana. Their
research also proves that the nine different types of canned tuna fish sold in Ghana shows that
their concentration level also lies below the allowable limit required. Thought in 2010 results
shows above there must be some differences in 2011 but the results remain constant.
Pourjafar H et al., (2014) on the similar topic from the same capital Tabriz (Iran) trying to
disprove Mehdi Zarei et al., (2010) &Baodi N.O et al., (2011) results by analyzing five different
types of canned tuna fish, however their results also lies somewhere below the world permissible
limit which is (0.01-0.242 ppm) for lead and cadmium lies below the detection limit. Again in
the same year (2011) Mani Mahalakshmi et al was carry out another similar type of research
done using processed canned tuna fish from Canada and India in which Canadian products are
used to analyze mercury and aluminium while Indian products are used to analyze cadmium and
lead. The results reported are below world required standard in the case of cadmium and lead but
for aluminum and mercury are higher therefore they concluded by saying that “canned tuna must
be monitored comprehensively and periodically with respect to the consumer health”.
Extremely all researchers carrying out similar research on this topic seemed to obtained results
with concentration below the world permissible limit. Since there are no available data on recent
studies this researcher tried to determine the concentration of heavy metals in canned tuna for
this year (2016) to see if there are any significant changes in the concentration level.
2.3: Physical, geographical, and socio-economic description of the study
environment
Estimation of about eighty per cent (80%) of people living in Lae city are unemployed and only
twenty per cent (20%) are employed. Due to the fact that most Morobeans are unemployed, the
economic value is too highly demanded, so the people will try to manage from the little they earn
to satisfy their daily basic needs. Sometimes people oversight and forgot to consider the quality
of the product and only choose according to its quantity. For this reason the customers go for the
products that are of most cheap and affordable prices to satisfy their daily needs and wants. It is
via this reason that most people chose tuna canned fish among all the canned fish products. This
is the main reason of Raumai 18 wholesale store at Eriku normally orders canned tuna fish in
bulk quantity than other brands of canned fish like sardine and mackerel due to the stock being

15
running out so quickly. It is scientifically believed that the more you consume contaminated
products, the more heavy metal you accumulate in the body and the more you destroy your own
body system to function well so people have to think twice and choose wisely before you regret.
2.4: Detailed discussion of Heavy metals
“Elements are the basic building blocks of all chemical compounds, and human exposure to them
occurs both from natural and anthropogenic sources” (Doctors Data Inc, 2016). Many elements
are considered nutritional and are essential for the proper functioning of the body. These are
generally divided between macro-minerals such as calcium (Ca), magnesium (Mg), potassium
(K), sodium (Na) and zinc (Zn), while trace minerals including selenium (Se), iodine (I), boron
(B) and molybdenum (Mo). However, their tendency of becoming toxic is also very high when
the body gets in excessive amount of those into the body which Lawrence Wilson has agreed by
stating in his research under toxic metals and detoxification saying that “Also, some forms of the
required minerals can be highly toxic. For examples are some forms of copper, iron, manganese,
hexavalent chromium selenium and others. Sometimes too much of those essential minerals can
also be toxic.
Conversely, there are a number of elements that are toxic to the human body, interfere with its
functioning and undermine health such as mercury (Hg), lead (Pb), cadmium (Cd), chromium
(Cr), and arsenic (As). These toxic metals have no known physiological functions in the human
tissue. They can be toxic to organ systems and may disrupt the balance of essential nutrients.
Toxic metals and essential element status can be assessed in urine, blood, feces and hair (Doctors
Data Inc, 2016).
A toxic substance is a chemical that is harmful for people or other living organisms. The effects
from exposure to a toxic substance may be acute or chronic. Acute effects are those that appear
shortly after exposure, usually to a larger concentration or doses over a short period of time.
Examples of acute effects are skin burns or rashes, eye irritation, chest pains, kidney damage,
head ache, convulsions, loss of appetite, and then finally death. Effects that are usually long-
lasting are called chronic effects. They may not appear for months to years after exposure and
usually last for years. Examples of chronic effects are cancers, lung and heart disease, birth
defects, genetic defects and nerve and behavioral disorders. Chronic effects often occur as a

16
result of prolonged exposure to fairly low concentrations or doses of a toxin in which prolonged
exposure to heavy metals results in chronic effects (Janarthana, 2015). In general, toxic
chemicals like heavy metals attack the active sites of enzymes inhibiting the essential enzyme
function because they have no useful function in the body. Heavy metal ions, in particular
(Pb2+& Cd2+) act as effective enzyme inhibitors. They have affinity for Sulphur containing
ligands. For example SCH3 and –SH in methionine and cysteine amino acids, which are part of
the enzyme structure. Pb and Cd are soft Lewis acids and so they love to bond with soft Lewis
bases like sulfhydryl linkage of cysteine residue. Normally, cysteine residues provide structurally
important cross-linking sites through the formation of disulphide bridges. Heavy metals interfere
with formation of such bridges (Janarthanan, 2015).
Metalloenzymes contain metals in their structure and their action is inhibited when one metal ion
of a metalloenzyme is replaced by another metal ion of similar size and charge. Thus Zn (II) in
some metalloenzymes is substituted by Cd (II) which leads to Cadmium toxicity. The enzyme
inhibited by Cd (II) includes adenosine triphosphate, alcohol dehydrogenase, carbonic anhydrase
and many more. Pb (II) inhibits acetylchoanesterase and some of the key enzymes in the
synthesis of hemoglobin (Janarthanan, 2015).
2.4.1 Causes and Effects of heavy metals in the body
Since they are harmful to the body in very low concentration, they eventually get accumulated in
the body since they don’t metabolize so easily. Lead present in the body causes mental
confusion, visual disturbances, convulsions, loss of cognitive abilities, anti-social behavior,
paralysis, anorexia, “lead line" on gum margin, nausea, vomiting, severe abdominal pain and
anemia while the presence of cadmium in the body causes extreme restlessness and irritability,
headache, chest pain, increased salivation, choking, vomiting, abdominal pain, diarrhea,
tenesmus, throat dryness, cough, pneumonitis (Janarthanan, 2015).
2.4.2. Lead
“Lead in the environment is mainly particulate bound with relatively low mobility and
bioavailability. Lead does, in general, not bio-accumulate and there is no increase in
concentration of the metal in food chains” (Heavy metal in waste, 2002).

17
Lead can cause disruption of heme synthesis leading to lack of utilization of oxygen and glucose
for life sustaining processes. A higher level of lead in blood leads to loss of appetite, anemia,
kidney malfunction, nervous disorder (Pb is neurotoxin) and brain damage. At intermediate
concentrations, however there is persuasive evidence that lead can have small subtle, subclinical
effects, particularly on neuro-physiological developmental in children.
The overall effect is the disruption of heme synthesis of hemoglobin as well as other respiratory
pigments, such as cytochromes which requires heme. Finally lead does not permit utilization of
oxygen and glucose for life sustaining energy production. This effect can be detected at high
level of ~0.3 ppm in the blood. At higher levels of lead in the blood (0.5-0.8 ppm), there will be
symptoms of anemia due to the deficiency of haemoglobin. Elevated Pb levels (>0.8) ppm in the
blood cause kidney dysfunction and finally brain damage.
Due to chemical analogy between Pb (II) and Ca (II), bones act as repositories for lead
accumulated by the body. Subsequently, this lead may be remobilized along with phosphates
from the bones which exert a toxic effect when transported to soft tissues (Janarthana, 2015).
Lead poisoning will be cured by feeding the patient with an aqueous solution of calcium
complex of EDTA. Below is a general equation showing the formation of EDTA complex with
Pb.
Ca-EDTA (Soluble) + Pb2+
= Pb-EDTA (soluble) + Ca2+
2.4.3. Cadmium
Cadmium occurs in nature in association to zinc minerals. Cadmium appears just next to zinc in
the periodic table and their shell structure is somewhat same therefore cadmium can easily
replace zinc when there is lack of zinc. The outbreak of cadmium poisoning occurred in Japan in
the form of itai-itai or “ouch ouch” disease is a type of disease where bones become fragile. At
high levels, Cd causes kidney malfunction, anemia and bone marrow disorders. The major
portion of cadmium ingested into our body is trapped in the kidneys and eliminated. It can be
able to live in the body over years. A small fraction is bound most effectively by the body
proteins, metallothipnein present in the kidneys, while the rest is stored in the body and gradually
accumulates with age. When excessive amounts of Cd (II) are ingested, it replaces Zn (II) at key

18
enzymatic sites, causing metabolic disorders (Janarthanan, 2015) then separated by one. There
are three technologies applicable for removing Cd from industrial waste waters. In waste water,
dissolved Cd can be either precipitated with sodium sulphide or it can be cemented by the
addition of zinc or separated out by ion exchange. If the cadmium is incorporated into
particulates, the Cd can be dissolved by the addition of acid and of the below techniques or the
solids can be settled out and the cadmium removed with the sludge.
1. CdCl+
(Chloro complex I sea water) + HS- =CdS(s) + H+ + Cl-
2. Cd2+
(aq) + Na2S = CdS(s)
3. Cd2+
(aq) + Zn(s) = Cd(s) + Zn2+
(aq)
4. Cd2+
(aq) + Na2[RESIN] = Cd[RESIN]2 + 2Na+ (aq)

19
CHAPTER THREE: METHODOLOGY
3.1. Introduction
Dryashing is a method that was applicable for the determination of cadmium and lead in canned
tuna fish. It has been reported that the major drawback to dry ashing is loss of metal due to
volatilization. However, the temperature in the muffle furnace was held at 500˚C, loss from
volatilization is minimal. The dry-ashing method was simple and less time consuming than the
digestion methods. The level of cadmium and lead are too low to be determined directly, solvent
extraction was applied to concentrate these elements.
Prior to that, sampling of all canned tuna fish are done, transported into the laboratory opened
and homogenized via a food blender and got preserved in the freezer below zero degree Celsius
to avoid contamination of the sample to preserve the analytes of interest for metal recovery.
Sample preparation was considered the most significant method employed in all the laboratories
around the world to bring the sample to its appropriate sizes prior to any analysis (“AOAC,”
1988). Analytical quality controls and assurance are applied to the sample along the process to
increase accuracy and precision of the analysis to obtain results of validity. Reagents of high
purity are employed to preserve samples of different types accordingly. Muffle furnace was
applied to obtain dry weight and also for ashing, nitric acid was applied to the sample to obtain
carbon-free ash and hydro-chloric acid was added to concentrate the analyte of interest. In this
section, temperature, pressure and time are the most significant parameters that are closely
monitored to valid the results of the analysis.
3.2: Method of Application
3.2.1: Dry ashing method
To determine bio-metals in biological animal and plant tissues. However in this research, the
method was applicable for the determination of bio-metals in fish tissues in the canned tuna fish
products especially the heavy metals such as Pb and Cd. This method was extracted out of the

20
AOAC standard method that has been recently applied and used by the Unitech Analytical
Services Laboratory (UASL).
3.2.2: Purpose of method
This method describes the procedures for the determination of levels of nutritional and toxic
elements commonly analyzed in tissues except for C, N, Si and Cl. The procedure was applicable
for samples of both animal and plant origin.
3.2.3: Scope or field of application
The samples homogenized via food blender and are stored in polyethylene containers in the
freezer. This was done to preserve the analyte so as the sample from contamination. Muffle
furnace are used primarily to obtain dry weight, nitric acid are applied to volatilize off all other
metals present in the test sample and to obtain carbon-free ash, and to concentrate the analyte
using nitric acid digestion. The samples are weighed and dried at 137OC
in the muffle furnace and
controlling the time. Digested on a hot plate to obtain carbon-free ash repeat until a carbon-free
ash is obtained using nitric acid. One normality of Hydro-chloric acid was used to concentrate
the analyte of interest and dilute to mark in a 25ml volumetric flask for analysis via ICP-OES.
3.3: Reagents
Analytical reagent grade are used.
 30% Ethanol (Rinsing blender)
 Concentrated nitric acid (digest)
 1N hydro-chloric acid (concentrating analyte)
 Distilled water(dilution).

21
3.3.1: Standards for ICP-OES
An extract of standard stock solution of Pb and Cd (1000mg/L) was pipetted into 25ml
volumetric flask to prepare secondary standard. Out of the secondary standards was prepared the
working standards in which the secondary standards are spiked with Nitric depending on the type
of stock standard used prior. Finally working standards are prepared out of the secondary
standards that was used to analyse via ICP-OES. The standards will be prepared using the
standard formula;
Figure 3: Standard formula for calculating the unknown concentration and volume
3.4. Sampling Equipment Preparation
Sampling equipment are the master key player in this research since they provide
accommodation for the analyte of interest which are the heavy metals and also act as a protecting
agent for any form of contamination, spillage, deterioration and exposure to atmospheric
contaminants. The sampling equipment are washed thoroughly with soap and 10% nitric acid to
fully sterilize all the necessary equipment for sampling and analysis and this was the standard
procedure normally applied before using a lab apparatus.
3.4.1: Procedures:
 Soak the necessary equipment in the sink or big containers with water for approximately
two days foe easy washing.
 Appropriate lab detergent was used for washing to further remove dirt and other
additional contaminants and bacteria for clean apparatus for usage.
 Air-dried the equipment and apparatus on the bench top to dryness.
Standard Formula
M1V1 = M2V2

22
 Soaked them again into another container containing 10% nitric acid for all other
equipment but soak the ICP-tubes in a separate bowl containing 10% hydrochloric acid to
purify the equipment thoroughly to remove all the unwanted chemicals and pollutants to
contaminate the sample while preparing and processing. Finally a final rinse with de-
ionized water and air-dry to evaporate of the water on the bench top ready for usage.
3.5: Sampling
Sample collection was done by the technical staffs. A duplicate of three canned tuna fish each
was bought with respect to the country of production and the manufacturing company. Actually
there was no need for observation to be done onsite since the samples are being packed and
ready for sample preparation and via ICP-OES.
3.6: Sample Preparation
 Labels removed
 Sample identification given to each brand.
 Opened canned tuna fish via fish opener.
 Homogenize via food blender
 Stored in polyethylene containers with lids carefully closed. Every after blending one
brand the blender was rinsed with 30% ethanol.
 Stored in freezer below zero degree Celsius.
 25g of wet weight was gently weighed into porcelain crucible and placed into muffle
furnace with a blank as the control without replicates due to the size of furnace and time
limitation and timed it for two hours after reaching 137°© .
 Dry weight obtained after being removed from muffle furnace and cooled in desiccator.
 The porcelain crucible were again placed back into the muffle furnace increased the
temperature to 500°© for overnight ash to obtain carbon free ash.

23
 The crucibles were removed cooled in desiccators and add 2mls concentration HNO3,
stirred carefully and placed them on the hotplate just to dryness.
 Again the crucibles are then inserted back into the muffle furnace, raise the temperature
to 500°© for exactly 2hours to obtain white clear precipitates.
 Gently the crucibles are removed let cooled to room temperature in the desiccators.
Finally 10mls of HCl was added to concentrate the solution and then was transferred in
the 25ml volumetric flask. The digest was then diluted to mark and sent into the
instrument room for analyses via ICP-OES.
Figure 3.2: Sample Preparation Chart
3.5.1: Dry-ashing Method
For each sample approximately 25g (wet weight) of homogenized fish tissue was weighed
accurately into four porcelain crucible in which each porcelain contain tissues of different brand

24
name with only one blank without any replicates nor reference material due to time limitation
and the size of muffle furnace. Placed in the muffle furnace and slowly raise temperature to
137°© for two hours to obtain dry weight for calculation. Removed and cooled in the desiccator
to room temperature and then placed it into the cooled muffle furnace again and raise the
temperature to 500°© doing overnight ash after the dry weight was obtained. Removed and
cooled to room temperature in the desiccator and add gently into 2mls of Con. HNO3 to obtain
carbon free ash and again the crucibles are then placed back into the muffle furnace after being
dried on the hotplate for 2 hours at 500°©. Removed and cooled to room temperature in the
desiccator. Again 10mls of HCl was gently pipetted into the porcelain crucible to concentrate the
digest. Placed on the hotplate to dissolve the white precipitates formed in the crucible to get into
the solution. The digest was then diluted with de-ionized water into a 25ml volumetric flask
ready for ICP-OES run.
Figure 3.3: Ratio of reagent used for sample preparation
3.6: Inductively Coupled Plasma-Optical Emission Spectrophotometer (ICP-OES) Analysis
After the dilution, the sample was sent over to the Unitech Analytical Services Laboratory
(UASL) for analyses via ICP-OES. Before that the instrument was calibrated using upper and
lower ranges working standards however, since lead and cadmium concentrations are lower,
standards prepared are between 0.1ppm to 10ppm.After the calibration the samples are detected
at their own characteristic wavelength in which the results are sent to the computer and data was
collected, calculations done on the collected data and was reported as parts per million (ppm).
Reagent
Conc. HNO3 :1N HCl
1:5 ratio

25
Figure 3.4: General view of how Inductively Coupled Plasma-Optical Emission
Spectrophotometer (ICP-OES) normally work
3.7: Analytical quality assurance and control
Both the quality control and quality assurance are often treated as the same but they are not.
Quality controls are measures that are used in the field sampling as well as analysis in the
laboratories while quality assurance are the assured actions with caution applied in handling the
problem to solve it with high quality.
In this research there are no field sampling applicable due to samples being already packed and
ready for transportation to the laboratory. In that case the analytical quality control and quality
assurance technique were applicable in the laboratory during sample preparation and analysis in
which only a blank was employed leaving out replicates and reference material due to so many
factors. The preparation are done in a clean condition with care and caution to avoid sample
contamination.

26
3.8: Data processing and analyses
Data processing and analysis was done automatically in the computer attached to the ICP-OES
instrument and the calculations of each results are done manually on Microsoft excel in tabulated
form following the standard format set that is applicable nation-wide.

27
CHAPTER FOUR: RESULTS
4.1: Introduction
This research was specifically carried out to compare the concentration of cadmium and lead in
canned tuna fish consumed by the people living within Morobe Province. In order to prove the
above stated theory of the research, the researcher was collecting test samples of canned tuna fish
of four different processing canneries in which two are of PNG and other two from overseas.
4.2: Results
Table 4.1: Table showing results obtained from ICP-OES
Sample Weight (g) Vol (ml) Cadmium (mg/L) Lead (mg/L)
25.036 25 1.37 0.366
25.078 25 0.371 0.138
25.253 25 2.24 0.477
25.161 25 2.27 0.786
4.3: Data analysis and statistical evaluation
A. Cadmium in canned tuna fish of four different brand types;
1. 1.37/25.036 X 25/1000
0.001µg/g
2. 0.371/25.078 X 25/1000
0.0003µg/g
3. 2.24/25.253 X 25/1000

28
0.002µg/g
4. 2.27/25.161 X 25/1000
0.002µg/g
The calculations shows that the cadmium concentration in canned tuna fish is lower than the
world permissible limit which is 0.05-0.5ppm.
The average level of cadmium concentration is calculated below:
(0.01) + (0.0003) + (0.002) + (0.002) = (0.0053)
(0.0053) ÷ (4) = (0.001325)
Mean = 0.001325
Range = 0.0003 – 0.002ppm of Cd in canned tuna fish
B. Lead in canned tuna fish of four different brand type;
1. 0.366/25.036 X 25/1000
0.0004µg/g
2. 0.138/25.078 X 25/1000
0.0001µg/g
3. 0.477/25.253 X 25/1000
0.0005µg/g
4. 0.786/25.161 X 25/1000
0.0008µg/g

29
The calculations shows that the lead concentration in canned tuna fish is lower than the world
permissible limit which is 0.4-0.5ppm.
The average level of cadmium concentration is calculated below:
(0.0004) + (0.0001) + (0.0005) + (0.0008) = (0.0018)
(0.0018) ÷ (4) = (0.00045)
Mean = 0.00045ppm
Range = 0.0001 – 0.0008ppmPb in canned tuna fish

30
CHAPTER FIVE: DISCUSSION
The hypothesis of this research states that the heavy metal concentration in the canned tuna fish
caught and processed in PNG is lower than the permitted concentration of heavy metals required by
the body compared to tuna products from other countries. This is has been disproved by saying that
all canned tuna regardless of the production site and the brand type contained lower concentration of
cadmium and lead which are much more lower than the FAO/WHO standard permitted limit.
All other researchers elsewhere carrying out similar research also proved that the heavy metal
concentration in the canned tuna fish are lower than the world permissible “Mehdi Zarei et al.,
(2010), Pourjafar H et al., (2014), Mani Mahalakshmi et at., (2011)

31
CHAPTER SIX: CONCLUSIONANDRECOMMENDATION
6.1: Conclusion
It can’t be concluded that all canned tuna fish sold in Morobe supermarkets are safe for human
consumption because there are only four types that were analysed. It can only be concluded directly
whether safe or not when all canned tuna fish sold in Lae supermarkets are analysed with controls.
However, when comparing all the related results obtained from other researchers, this research
tend to agree with other researchers saying that despite the fact of tuna it is safe for consumption
in which it has been scientifically proven that they are safe and good protein for body
development since results are well below the permissible limit which are (0.4-0.5 & 0.05-
0.5ppm) for lead and cadmium respectively.
6.2. Recommendations
 I would suggest further research on this particular topic to prove that this results are
accurate since there are so many issues on heavy metals affecting people nowadays.

32
REFERENCES
Ahmed Q & BatL, Heavy metal levels in Euthynnusaffinis (Cantor 1849) Kawakawa fish
marketed at Karachi Fish Harbour, Pakistan and potential risk to human health. J. Black
Sea/Mediterranean Environment Vol. 21, No. 1: 35-44 (2015)
(Al-Mutarri, 2015) (Mohammad Malakootian1; Mahsa Tahergorabi2; Mohammad
Daneshpajooh3; Kiomars Amirtaheri4, 2011)
AN. Sabramanian, Marine Environment. Centre for Marine Environmental Studies, Ehime
University, Japan, Department of Water (2009). Water quality monitoring design. A guideline to
the development of surface water quality monitoring programs. Government of Western
Australia.
Doctors Data Inc (2016). Science + Insight-A clinical laboratory providing innovative accurate
specialty testing.
Environmental Protection Agency Victoria (2016). United States Environmental Protection
Agency -Your environment. Last updated, January 5 (2016)
European Commission DG ENV. E3 Project ENV.E.3/ETU/2000/0058
Heavy Metals in Waste, Final Report February 2002 COWI A/
Evans M. (2011).Fishing.Earth. Times. www.earthtimes.org. June 03 2011 08: 35: 01
Encyclopaedia 2016
(F. Emami Khansari a,b, M. Ghazi-Khansari a,*, M. Abdollahi, 2005) (Al-Mutarri, 2015)
Human Rights Watch (2010).Mercury-A Health and Human Rights Issue. Towards a global
treaty on mercury. hrw.org
(Mani Mahalakshmi, Srinivasan Balakrishnan*, Kalyanasundram Indira and Muthukumarasamy
Srinivasan, 2011)

33
(Mehdi Zarei, Sara Pakfetrat, Shahram Shekarforoush,Alireza Mollaie, Mohammad Hadi
Eskandari,, 2010)
NMA. Shazili, et at. Aquatic Ecosystem Health and Management. Doi:10.1 (Journal of
Toxicology and Environmental Health Sciences Vol. 4(2), pp. 43-45, February 2012,
2011)080/14634980600724023 (pg.137-145)
(N.O. Boadi, S.K.Twumasi, M. Badu and I. Osei, 2011)
Plataforma SINC. "Transfer Of Heavy Metals From Water To Fish Detailed In Huelva Estuary,
Spain." ScienceDaily, 16 June 2009.
<www.sciencedaily.com/releases/2009/06/090616080909.htm>.
(Pourjafar, H.1*, Ghasemnejad, R.2, Noori, N.1, Mohammadi, Kh.3, 2014) (F. Emami Khansari
a,b, M. Ghazi-Khansari a,*, M. Abdollahi, 2005)
Seafood International. The world’s top ten seafood superpower nation. Copyright 2015 powered
by Monster development.
Symptoms of Elemental Toxicities. Many of our toys have toxic potentials- Very little is too
much-Very small quantities of these atoms can cause serious biological damage.
World Meteorologist Organization (2013).Planning of water quality monitoring systems:
weather-climate-water. NMO-No. 1113. Switzerland.
W. Lawrence, 2015. Toxic metals and detoxification. The centre for development. @ June, 2015.

34
APPENDICES
APPENDIX A: A MAP SHOWING MOROBE PROVINCE IN PAPUA NEW GUINEA.
APPENDIX B: SHOWING HOW THE SAMPLE PREPARATION WAS DONE

35
APPENDIX C: SHOWING HOW THE ICP-OES WORKS

Final Report 402

Recommended

Recommended

More Related Content

What's hot

What's hot (15)

Viewers also liked

Viewers also liked (16)

Similar to Final Report 402

Similar to Final Report 402 (20)

Final Report 402