The document discusses arsenic and fluoride contamination of drinking water. It provides background on sources of arsenic and fluoride in the environment and their health effects. It also describes various technologies for removing arsenic and fluoride from drinking water, such as iron nails in biosand filters and ion exchange resins. Guidelines for safe levels of arsenic and fluoride in drinking water from different organizations are presented.

1. Arsenic and Fluoride 2007-07

2. 2007-07 Zheng Gong, MIT department of Civil and Environmental Engineering, August 2005 Over 30 countries in the world is affected by arsenic in drinking water

5. 2007-07 Baseline Arsenic in the Environment Water Source Typical baseline concentrations Atmospheric precipitation (rain and snow) Usually < 0.03 ug/L River water Usually < 2 ug/L Lake water Usually < 1 ug/L Seawater Usually about 1.5 ug/L Groundwater Usually < 10 ug/L

7. Chronic Health Effects Source: Harvard University. “Harvard Arsenic Project.” Internet. Accessed Sep 27, 05. http://phys4.harvard.edu/%7Ewilson/arsenic/arsenic_project_introduction.html After melanosis, keratosis and other lesions may occur Keratosis is the hardening skin bulges on palms and feet

8. 2007-07 Guideline Value in Drinking Water WHO 10 ug/L(ppb) = 0.01 mg/L (ppm) Australia 7 ug/L Canada 25 ug/L EU 10 ug/L Japan 10 ug/L USA 10 ug/L Bangladesh 50 ug/L Cambodia 50 ug/L China 50 ug/L India 50 ug/L Lao 50 ug/L Myanmar 50 ug/L Nepal 50 ug/L Pakistan 50 ug/L Vietnam 10 ug/L urban, 50 ug/L rural Source: World Bank. Towards a More Effective Operational Response. Volume 1. 2005

11. Diffuser Basin Brick Chips / Iron Nails Outlet Pipe Filter Lid Fine Sand Layer Standing Water Layer Separating Gravel Under drain Gravel

12. THE REMOVAL OF ARSENIC By adding 5 kg (11lbs) of small non-galvanized iron nails, covered by a layer of brick chips, the Biosand filter can remove a certain level of arsenic from water. This is accomplished by replacing the diffuser plate with a deep diffuser basin. The iron nails in the diffuser basin, after contact with water and air, will quickly rust. Iron rust (ferric hydroxide) is an excellent adsorbent for arsenic. When arsenic-containing water is poured into the filter, surface reactions with iron occurs, and arsenic is rapidly adsorbed onto the surface of ferric hydroxide particles . The arsenic loaded iron particles are then flushed down and trapped on top of fine sand. The purpose of the brick chips is to disperse the water over the nails to allow for further absorption.

14. 2007-07 Diffuser Basin Lid Container Pipe Kanchan TM Arsenic Filter Components Gravel Coarse Sand Water Fine Sand Iron Nails Brick chips

16. 2007-07

17. 2007-07 Arsenic Symptoms, Diagnosis and Treatment UPdate Summer 2002 Diagnosis of arsenic poisoning, especially from low doses of inorganic arsenic, the type found in CCA lumber, is not easy. There is no one set of symptoms. Different people respond differently, depending on how much exposure they get, and by what means. Arsenic can be inhaled, ingested (swallowed) or absorbed through contact. Arsenic poisoning is difficult to pin down because most of the arsenic leaves the body within three days of exposure. The arsenic which remains is stored in the brain, bones, and tissue and continues to do serious damage. Some people have no immediate symptoms, but the exposure can cause many types of cancer or diabetes later on. T There is new evidence that arsenic may also lead to heart disease or strokes. It may cause long term liver, kidney, and central nervous system damage.

18. Arsenic exposure, even at low levels, can result in a range of symptoms. Swallowing or inhaling low levels of inorganic arsenic can result in stomach ache, nausea, vomiting and diarrhea. It can also result in decreased production of red and white blood cells which may cause fatigue, abnormal heart rhythm, blood-vessel damage resulting in bruising, and impaired nerve function. One of the early warning signs of arsenic poisoning is a &quot;pins and needles&quot; sensation in hands and feet. Long-term oral exposure to inorganic arsenic can result in skin changes including a darkening of the skin and the appearance of small &quot;corns&quot; or &quot;warts&quot; on the palms, soles, and torso.

19. 2007-07 Other signs and symptoms include skin thickening, fluid accumulation (resulting in puffiness) especially around the lower eyelids, face and ankles, diarrhea, garlic breath, perspiration, excessive salivation, generalized itching, oral inflammation, sore throat, runny nose, excessive tearing, numbness, skin inflammation, hair loss, weakness, and loss of appetite. Arsenic can also cause a range of neurological effects, including headaches and vision problems. It can cause noticeable behavioral changes, most commonly aggression or depression.

20. 2007-07 Because most arsenic leaves your body within a few days, analysis of urine cannot detect if a person was exposed to arsenic in the past. Tests of hair or fingernails can determine exposure to high levels of arsenic over the past 6-12 months, but these tests are not very useful in detecting low-level exposures. Early treatment of arsenic poisoning is critical. The longer arsenic remains in the body, the more damage is done. If arsenic poisoning is determined, oxygen therapy, chelation therapy, saunas and other methods used for detoxification of heavy metals is the usual treatment. There is some new information that selenium may help decrease the effects of arsenic. Naturopaths may be able to help with diagnosis and treatment with other methods.

21. Defluoridation of Drinking Water 2007-07

24. Fluoride Guidelines 2007-07 Dose Symptoms < 0.5 mg/L Susceptibility to dental caries 0.5 - 1.0 mg/L Lower dental caries 1.5 - 4 mg/L Dental fluorosis > 4 mg/L Dental and skeletal fluorosis >10 mg/L Cripping fluorosis