DDT levels Developed countries have low levels of DDT in human milk in comparision to developing countries

Adapted from: F Ejobi et al 1996, Organochlorine pesticide residue in mother’s milk in Uganda, Bulletin of Environmental Contamination and Toxicology, 56:875, New York.

Diseases, ailments and syndromes that have commonly been attributed to chemicals are cancers (to dioxins, pesticides and metals), neurological disorders like Alzheimer’s disease (to aluminium), eczema (to hardness of water) and diabetes mellitus (to increased nitrates in water). Cancers like bladder cancer and non-Hodgkin’s lymphoma are strongly associated with the high presence of nitrates in water.3 A study of children in five villages in Rajasthan found that high nitrate ingestion in drinking water together with methemoglobinemia, causes and aggravates recurrent acute respiratory tract infections and may be the reason for high mortality in children.4 Even "safer" pesticides used in homes have been incriminated to cause Parkinson’s disease, 5 breast cancer 6 and cognitive dysfunction.7 Risks are often widespread and across borders. In Turkmenistan, for example, dust is richly laden with hazardous pesticides, carried from neighbouring countries and regions. This dust contains anywhere between 1. 8 to 126 milligrams of particulate matter per kilogram of dust deposited per hectare of land. Evidence suggests that there is an increase in interstitial lung disease in children in the region8. Parental occupation also poses risks to children 9, 10,11.

Reproductive disorders from endocrine disruptors, hormonally-related cancers, and infertility also appear to be on the rise. During the past 50 years, the rate of testicular cancer in industrialised countries has increased by a factor of two to four. Breast cancer mortality in the United States has been rising by about one per cent per year since the 1940s. There is some evidence that sperm counts and semen volume may have declined substantially.12 There are also signs that abnormal sexual development in infants may be increasing. A doubling of the incidence of undescended testes in male infants since 1960 has been reported in the United Kingdom.13 Today’s increased prevalence of these reproductive problems is puzzling. Some increases in cancer rates have occurred in the elderly but more disturbingly, these symptoms have also been observed in younger populations. Most studies on these phenomena conclude that long-term exposure, initiated in childhood was responsible for these conditions. However, so far no studies on these issues have been done in India.

…or absence of evidence?
The sudden rise of modern disease epidemics has taken the Indian medical fraternity by surprise. Physicians in Mumbai, for example, found they were under-diagnosing asthma. The prevalence was actually 17 per cent, compared with 3.5 per cent by physician diagnosis.14 Similarly, unexplained rise in the number of cancer patients from areas not considered "hotspots" for cancers is alarming doctors in India. In Delhi alone, six new cancer treatment hospitals have sprung up in the past five years. Even the many Government of India registries show that cancers are on the rise in children (though, shockingly, the government has not produced a comprehensive report for about a decade!). What is even more alarming is that the numbers of unexplained causes of child deaths have increased dramatically.

Pesticides that have long been phased out in developed countries, and banned/restricted food additives and preservatives are liberally marketed in India. Enforcement agencies like the Bureau of India Standards, pollution control boards and more importantly the Ministry of Health and Family Welfare have no synergy or cooperation to deal with these challenges. Clearly, enforcement and regulatory agencies are keen to adopt best prevailing standards but are at least a generation behind in implementing them.

Killer air…

At last there now comes conclusive evidence that tiny particles in the air increase the risk of human death. A recent study published in the Journal of American Medical Association, co-authored by C Arden Pope, professor of economics at the Brigham Young University finds that a mere increase of 10 microgrammes per cubic metre (µg/cu.m) of fine particles (size less than 2.5 microns or PM2.5) increases the risk of lung cancer by 8 per cent, that of cardiopulmonary deaths by 6 per cent and all deaths by 4 per cent. To really understand how air pollution results in increased risk for lung cancer, the effect of smoking on lung cancer risk was taken into account. The study thus help provide new insights into lung cancer risk. The research took place over a period of sixteen years, covering 116 metropolitan areas of United States and covered about 500,000 people. The study is a part of the ongoing prospective mortality study of approximately 1.2 million adults, the analysis of which is based on the data collected by the American Cancer Society. "The findings of this study provide the strongest evidence to date that long-term exposure to air pollution, common to many metropolitan areas in the US, is an important risk factor for cardiopulmonary and lung cancer mortality," according to Pope. The study shows that despite improvements in the falling rates of fine particulate levels, the levels are still high enough to be associated with a significantly increased risk of cancer and cardiopulmonary deaths. In 1999-2000, the annual average particulate air pollution level recorded in New York was 16 µg/cu.m, with Los Angeles, Chicago and Washington, DC reporting 20 µg/cu.m, 18 µg/cu.m and 15 µg/cu.m respectively. Compare this to the levels recorded during 1979-1983: New York City 24 µg/cu.m, Los Angeles 27 µg/cu.m, Chicago 23 µg/cu.m and Washington DC 15 µg/cu.m. Yet, the risks to human health remain high. With air quality levels in most of the Indian cities higher than expected, it is not a surprise to come across more incidences of respiratory illnesses, breathlessness and reduced lung function. In Delhi alone, about 7.5-10 per cent of males suffer from various respiratory diseases. Clearly, the time has come to ask for our right to clean air.

The concept of environmental health has emerged only in the past 30 years or so and is yet to receive recognition from medical fraternity. The warning given in Rachel Carson’s Silent Spring (1962) that pesticides were creating greater problems than they were intended to solve-started off a controversy still raging today between environmentalists and the pesticide industry. More evident and large-scale disasters like Bhopal, Soveso dioxin poisoning, the Minamata mercury poisoning have moved governments to create effective policy measures and regulatory bodies, but it does not seem to have deterred industries from producing chemicals or at least conduct studies on their safety and long term implications. Therefore educating people on the impact of chemicals and toxics in their daily life is more important and more effective in bringing about this change. Modern diseases are the driving force of environmental health as a discipline in the developed countries. But India suffers from a double burden of diseases which pose more questions and reveals few answers on how they will interact and impact children. The needs to approach is of integrating health and environment, both in the research agenda, policy domain and in clinical diagnosis and treatment by medical practitioners. So far, environmental causes to diseases are not considered in the "radar" of diagnosis. But there is hope that with increase in awareness, this mindset will change and there will be more holistic approach to diseases.

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References 1-2. National Toxicology Program Studies available at www.ntp-server.niehs.nih.gov (as on March 12, 2002). 3. Peter Weyer 2001, Nitrate in Drinking Water Increases Bladder Cancer Risk, FDA Center for Food Safety and Applied Nutrition, Consumer Advisory, April 11, http://www.cfsan.fda.gov/~dms/supplmnt.html. 4. Sunil Kumar Gupta et al 2000, Recurrent acute respiratory tract infections in areas with high nitrate concentrations in drinking water, Environmental Health Perspectives, Vol 108, Number 4, April. 5. Joan Stephenson 2001, Exposure to Home pesticides linked to Parkinson disease, Journal of American Medical Association;283: 23,p 3055; and Alessandra Menegon et al 1998, Parkinson’s disease, pesticides, and glutathione transferase polymorphisms, The Lancet, Vol 352, October 24, p 1344. 6. Annette Pernille Høyer et al 1998, Organochlorine exposure and risk of breast cancer, The Lancet, Vol 352, December 5. 7. H Bosma et al 2000, Pesticide exposure and risk of mild cognitive dysfunction, The Lancet, Vol 365, September 9. 8. Sarah L O’Hara et al 2000, Exposure to airborne dust contaminated with pesticide in the Aral Sea region, The Lancet, Vol 355, February 19, p 627. 9. E Tielemans et al 1999, Pesticide exposure and decreased fertilisation rates in vitro, The Lancet; 354: p 484-85. 10. C Infante-Rivard et al 1991, Risk factors for cancer in the workplace. Boca Raton, FL: CRC Press. 11. L M Anderson et al 1994, Preconception exposure of males and neoplasia in their progeny: effect of metals and consideration of mechanisms. in: D R Mattison, A F Olshan, eds. Male-mediated developmental toxicity. New York: Plenum Press. 12. E Carlsen et al 1992, Evidence for decreasing quality of sperm of semen during past 50 years, British Medical Journal; 304:609-613. 13. Anon 1986, The World in Medicine 1986, British Medical Journal; 293:1401-1404. 14. Anon 1998, Editorial, Journal of American Medical Association, Vol 280, No 10, September 9, p 873.

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