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RESEARCH
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Prevention Measures . LIFESTYLE, NUTRITION AND LEAD POISONING Dr. Padmanabhan P. Nair It gives me great pleasure to be here today to speak on a topic of great importance to the health of a major segment of the human race. In this regard I should express my deep appreciation to The George Foundation and Dr. Abraham George for inviting me to participate in this conference. Since this is a pre-luncheon talk, permit me to address the larger question of lead as an environmental problem and the relationship between lifestyle, nutrition and the consequences of lead exposure. The Johns Hopkins University School of Hygiene and Public Health has been at the forefront on issues concerning environmental health, particularly, lead in the environment. I should recall the signal contributions of Dr. Julian Chisholm and the late Dr. Emanuel Kaplan for having recognized the high incidence of lead poisoning among inner city children in Baltimore. In this city, lead-based paint and plaster in older buildings used to be a major source of lead, and legislation was finally put in place to ban these products from commerce. . Lead or plumbum is romantically linked with the very beginnings of mankind - its origins being traced to antiquity. Among the earliest of metals to be discovered and used, lead has played a prominent role in human activity. Although there is no Lead Age to rival the Copper, Bronze and Iron ages, this metal has appeared in art, medicine and industry. Among metals this ranks at the top in tonnage produced and released globally into the environment. The Greek mines at Laurium were functioning well before 3000 BC and the mines of the Iberian Peninsula beginning with the Iron Age were celebrated for their role in bringing prosperity to that region of the world. In addition, historically, the landmass from Persia to Japan had also contributed significantly to the worldwide flux of anthropogenic lead estimated at between 5000 and 10,000 tons of atmospheric lead during the Roman era. From about 500 to 1500 AD environmental lead has fluctuated between 500 and 1500 tons a year. Then came a steep increase in global lead emissions around 1750 AD which peaked at around 400,000 tons/year in the decade, 1970-1980. Leaded automobile fuels accounted for a significant part of this global burden along with other industrial uses of lead. In recent years we have seen a decline in atmospheric lead to about 100,000 tons/year largely as a result of the introduction of unleaded fuels in Western countries. This brings up an important point about the geographic distribution of lead pollution. The effects of pollution control has produced an uneven distribution of environmental lead - a steady decline in environmental lead in developed countries in contrast to a continuing rise in developing countries. I am specifically referring to Asia and that region’s newly industrialized nations, as they struggle to contain this problem. Apart from atmospheric lead, this element is the most widely used in everyday life. Historically, clear lead glaze was used on decorative vases, drinking goblets and other common utensils dating back to the Hellenistic era. It was common place in Roman times to drink wine out of lead-based pewter goblets - a practice suspected to have ultimately crippled the Roman Empire. Although infants and children are the most susceptible to the effects of lead, adults are also affected to varying degrees. Even British royalty in the 18th Century suffered from the neurological disabilities that were initially attributed to an inherited defect in porphyrin metabolism. King George III suffered violent episodes of nervous breakdown, paralysis and delirium, which appeared to be madness to his ministers. Recent conjecture leads to the suspicion that he suffered from chronic lead poisoning with tainted wine - the lead having leached out of the original royal casks. This metal is one of the most ubiquitous in our environment, and it appears in the most unlikely of places and can exert a profound effect on human health. The effects are insidious, chronic, and disabling. Prevention strategies include most importantly; bringing about public awareness of this problem and introduction of counter measures as a matter of public policy coupled with sustained international cooperation. Industrial smokestacks are a source of a galaxy of pollutants - lead mercury, arsenic, and cadmium - oxides of nitrogen and so on. In many countries in the developing world there are very few laws regulating the discharge of such pollutants into the atmosphere. Quite likely they do not have an environmental expert or industrial hygienist to monitor the effluents which brings up the important question, - are we preparing these nations to develop the necessary infrastructure to meet the human resources needed to monitor these industrial units? Chart I presents an outline of the different sources of lead in the home and in the environment. Cosmetics, particularly eye makeup, are a notable source of lead pigment in many instances. Painting the eyes of infants with black eye makeup is a common cultural practice in India and other countries of that region. Paints and wall plaster form another source of lead in the domestic scene. Plaster has been a major source of lead in inner cities of the United States, where lead used to be a major additive to plaster. In the environment, air, water and soil are all potential sources of lead depending upon the locality. Urban industrial centers are more likely to be heavily contaminated - in the air and water and to some extent the soil. As I had indicated earlier, automobile exhaust is the prime culprit in the urban setting. In contrast, when we look at the old battlefields of Vietnam, Cambodia, Bosnia or the Middle East, there are large numbers of spent shells which are potentially lethal from the standpoint of their contribution of lead to the subsurface water table. Acid rain exacerbates this condition by increasing the runoffs from spent shells. In addition lead storage batteries in the industrial sector accounts for a significant source of lead as an occupational hazard. Now we have come to a very important point. The contribution of leaded fuels to atmospheric lead in urban areas. Here is a challenge for the environmentalist. This calls for some creative solutions. Here I am willing to stake my reputation to make a concrete proposal for a country like India. I feel this strategy should be adopted as a national policy. As we all know oxygenated fuels are less polluting since they are clean burning and can be unleaded. Alcohol produced from agricultural waste can be blended into gasoline to form a non-polluting unleaded fuel. Imagine, illicit liquor is a cottage industry in this country and the state is saddled with a heavy financial burden enforcing the excise laws. I am suggesting that all these illegal operations be brought under a cooperative umbrella where the alcohol produced by these small-scale units be purchased and utilized for the manufacture of oxygenated automobile fuels. It is estimated that up to 30% of the hydrocarbon content of regular gasoline can be replaced by alcohol without modifications to the internal combustion engine of present day cars. Imagine its impact on the cost of petroleum imports - almost a straight 20% lowering of imports of crude - a significant reduction in the dependence on imported oil as well as a measure of conserving fossil fuels. Imagine the impact on illicit liquor trade - they no longer operate outside the bounds of law - the State saves a significant amount of money from not having to field a large enforcement directorate. I call upon my colleagues in this audience to take this message to the people and to their elected representatives. Let us examine for a moment those who are at maximum risk for lead toxicity. First and foremost is the developing fetus. Pregnant women exposed to lead can transfer a significant amount of this metal to the developing fetus. This can result in premature birth, low birth weight or even abortion. Infants born of mothers exposed to high levels of lead show significant signs of neurological deficits. Children are particularly at risk with toys or objects contaminated with lead-containing dirt (which is plentiful in an urban environment). And in children, lead that enters the system is more readily absorbed and they are also more sensitive to their effects. In infants and young children, exposure to lead has been shown to decrease intelligence (IQ) scores, slow their growth and cause hearing problems and kidney damage. These effects are persistent, they interfere with school performance and these effects are caused by exposure to such low levels of lead, which were once thought to be safe. Nutritional status of these infants and children appears to be an important modulator. Here, iron status is the major determinant. Iron deficiency and lead toxicity can be synergistic and potentially devastating. Up to 50% more lead may be absorbed in children with iron deficiency anemia compared to those who are iron sufficient. A major contributory factor to the exacerbation of lead toxicity is iron deficiency anemia. In the tropics, iron deficiency anemia is a major health hazard among children caused either by a true deficiency in dietary intake or caused secondarily by intestinal parasitism - hookworm, pinworm, roundworm and so on. The eradication of intestinal parasites should be undertaken along with measures to prevent reinfestation. In any public health campaign, the first and foremost is public awareness. Unless and until we have an informed public with a minimum level of understanding about diseases and their causation, we will perpetuate this cycle of poverty, ill health, disease and death. It is therefore essential that, as a part of national policy, budgetary outlays should place great emphasis on raising the level of literacy. In every society showing an improvement in female literacy, there has been a parallel rise in the quality of life. It has been clearly shown by the experience in Kerala, Sri Lanka and Costa Rica that women’s education and female literacy were the salient factors that contributed to the high level of quality of life indices such as life expectancy, infant mortality and survival, and control on population growth. In many countries children form a significant segment of working society. They are underage, overworked, deprived of a normal childhood with little or no schooling. In their work environment, they are exposed to heavy metals such as lead under the most inhospitable surroundings. Appropriate remedial measures should be instituted to alleviate this problem. There is a crying need to bring about reforms in child labor laws and in their enforcement. With rapid industrialization of the developing world we face a new set of demographics. Flight to the cities has resulted in a population movement into areas of urban sprawl increasing the at risk segment of society. This translocation into the industrial heartland of various nations places a heavy burden on civic resources, increases pollution and again exposes an increasing number of citizens to the undesirable effects of lead and other environmental pollutants. Truly, there is no lead level in blood that can be considered to be safe for infants and young children. New evidence is accumulating to show that other physiological factors can alter the manifestations of lead toxicity - such that even at 10 mcg/dl of blood lead serious consequences are encountered. An insidious progression of non-specific symptoms - irritability, abdominal pain, diarrhea, colic, lethargy followed by kidney failure and/or neurological damage. In urban areas almost 90% of the lead in the atmosphere comes from the burning of leaded petrol. Traffic policemen are extremely vulnerable. Other sources are - industrial emissions, smelting operations, lead-acid battery manufacturing and lead based paints and pigments. Cigarette smoke is a source of lead. So people who smoke or breathe in tobacco smoke are exposed to more lead than those who are non-smokers or are not exposed to cigarette smoke. Lead can also migrate into dust and soil from such sources as hazardous waste dumps, fertilizers containing sewage sludge and from the exhaust of cars and trucks. Chart II summarizes the overall strategies for the reduction of lead poisoning. They are based on two ideas - the first is identification of major sources of environmental lead and its removal - and the second is the development of human resources for the implementation of preventive measures. In conclusion I strongly urge that alleviation of environmental hazards (such as lead) should be an integral part of public policy. The confluence of civic enlightenment, preventive strategies and cooperation from international funding agencies should prove effective in combating this global scourge. CHART I. SOURCES FOR ENVIRONMENTAL LEAD . HOME cosmetics ceramic pottery (lead glaze) burning contaminated firewood or kerosene indigenous remedies tobacco and tobacco products drinking water (polluted) plaster toys ENVIRONMENT automobile exhaust industrial effluents lead acid batteries ammunition (acid rain leachates) paints and varnishes contaminated aquifers water pipes CHART II. STRATEGIES FOR PREVENTION OF LEAD POISONING
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