Toxicology is a scientific discipline, overlapping with biology, chemistry, pharmacology, and medicine, that involves the study of the adverse effects of chemical substances on living organisms and the practice of diagnosing and treating exposures to toxins and toxicants. Toxicity is the degree to which a chemical substance or a particular mixture of substances can damage an organism History Ecotoxicology is a relatively young discipline that made its debuts in the 1970s Ecotoxicology emerged after pollution events that occurred after World War II heightened awareness on the impact of toxic chemical and wastewater discharges towards humankind and the environment The term « Ecotoxicology » was used for the first time in 1969 by René Truhaut, a toxicologist, during an environmental conference in Stockholm.

1. ECOTOXICOLOGY & ECOTOXICITY
MSC/ BS/ URDU/ HINDI
NOSHABA MUNAWAR

2. ECOTOXICOLOGY & ECOTOXICITY
Toxicology
• is a scientific discipline, overlapping with biology, chemistry, pharmacology,
and medicine, that involves the study of the adverse effects of chemical
substances on living organisms and the practice
of diagnosing and treating exposures to toxins and toxicants.
Toxicity
• is the degree to which a chemical substance or a particular mixture of substances
can damage an organism
identify the
nature of (an
illness o) by
examination
of the
symptoms.

3. ECOTOXICOLOGY & ECOTOXICITY
• Ecotoxicology
• is the study of the effects
of toxic chemicals on biological organisms, especially at
the population, community, ecosystem, and biosphere levels. Ecotoxicology is a
multidisciplinary field, which integrates toxicology and ecology.

4. ECOTOXICOLOGY & ECOTOXICITY
• History
• Ecotoxicology is a relatively young discipline that made its debuts in the 1970s
• Ecotoxicology emerged after pollution events that occurred after World War II
heightened awareness on the impact of toxic chemical and wastewater discharges
towards humankind and the environment
• The term « Ecotoxicology » was used for the first time in 1969 by René Truhaut, a
toxicologist, during an environmental conference in Stockholm.

5. ECOTOXICOLOGY & ECOTOXICITY
• Ecotoxicity,
• the subject of study of the field toxicology refers to the potential
for biological, chemical or physical stressors to affect ecosystems.
• Such stressors might occur in the natural environment at densities, concentrations
or levels high enough to disrupt the natural biochemistry, physiology, behavior
and interactions of the living organisms that comprise the ecosystem.

6. ECOTOXICOLOGY & ECOTOXICITY
• Everyday hazards
• people buy such products to support a clean and healthy home
• Canadians spend more than $275 million
• Chemicals from these cleaners enter our bodies through air passageways
• when these cleaning products are washed down the drain they negatively
affect aquatic ecosystems

7. PHOSPHATES
• Phosphates are found in many dishwasher detergents, laundry detergents, and
bathroom cleaners.
• They act as a fertilizer in water and in high concentrations can promote algae
blooms and increase weed growth.
• When water containing phosphates are washed into water areas they carry with
them fertilizers, nutrients, and wastes from the land.
• Phytoplankton and algae flourish at the surface due to increased phosphates
• Due to the increased number of decomposers that use more oxygen, fish and
shrimp at the lower layers of the ocean become oxygen-starved

8. OIL SPILLS
• One of the major environmental impacts of oil exploration on the environment is
the contamination of aquatic ecosystems from oil spills and oil seepages from
pits.

9. PESTICIDES
• Pesticides often pose serious problems as they kill not only targeted organisms
but also non-targeted organisms in the process.
• They are released into the natural environment intentionally by people who are
often unaware that the chemicals will travel further than anticipated,
• Thus the pesticides largely affect the natural communities in which they are
used. They negatively effect multiple levels ranging from molecules to tissues to
organs to individuals to populations and onto communities.

10. FRAGRANCE CHEMICALS
• Fragrance chemicals are found in most cleaning products, perfumes, and personal
care products.
• More than 3000 chemicals are used in these fragrance mixtures.
• synthetic musks used in detergents accumulate in the environment and are harmful to
aquatic organisms.
• Certain musks are possible endocrine disruptors that interfere with hormone functioning.

12. ECOTOXICITY TESTING
• Acute and chronic toxicity tests are performed for terrestrial organisms including
avian, mammalian, nontarget arthropods, and earthworms.
• The Organization for Economic Cooperation and Development (OECD) test
guideline has developed specific tests to test toxicity level in organisms.
Ecotoxicological studies are generally performed in compliance with international
guidelines, including EPA, OECD, EPPO, OPPTTS, SETAC, IOBC, and JMAFF.

13. ECOTOXICITY TESTING
• LC50 (Lethal concentration) is the acute toxicity test that tests for the concentrate
of tissue at which it is lethal to 50% within the test-specified time. The test may
start with eggs, embryos, or juveniles and last from 7 to 200 days.
• EC50 (Effective concentration) is the concentration that causes adverse effects in
50% of the test organisms (for a binary yes/no effect such as mortality or a
specified sublethal effect) or causes a 50% (usually) reduction in a non-binary
parameter such as growth.

14. ECOTOXICITY TESTING
• Endocrine Disruptor Screening Program (EDSP)
• Endangered species assessments.
• Bioaccumulation in fish using the Bioconcentration Factor (BCF) methods.

15. EFFECTS OF ECOTOXICITY ON A COMMUNITY
• Predator-prey relationships – either the predator is affected by the toxin resulting
in a decline of predator population and thus increasing the prey population
• Community ecotoxicology studies the effects of all contaminants on patterns and
species abundance, diversity, community composition, and species interactions.
• A species could be easily wiped out to the expense of a contamination from
foreign chemicals. Protecting distinct community levels, such as species richness
and diversity is essential for maintaining a healthy, well-balanced ecosystem

16. OVERALL EFFECTS
• Chemicals are shown to prohibit the growth of seed germination of an
arrangement of different plant species.
• Plants are what make up the most vital trophic level of the biomass pyramids,
known as the primary producers.
• Because they are at the bottom of the pyramid, every other organism in an
ecosystem relies on the health and abundance of the primary producers in order
to survive.

17. • If plants are battling problems with diseases relating to exposure to chemicals,
other organisms will either die because of starvation or obtain the disease by
eating the plants or animals already infected.
• So ecotoxicology is an ongoing battle that stems from many sources and can
affect everything and everyone in an ecosystem