Harmful effects of exposure to Toxic chemicals and pesticides.

Dr. P S Nerwal
LL.B, LL.M, PhD,
Ex IRTS officer & Ex Member, Railway Claims Tribunal.

Persistent Organic Pollutants are chemicals, industrial byproducts and pesticides which are very injurious to health of human beings, plants and animals. Toxic substances often have long latency periods. World over, thousands of deaths result annually from cancer due to exposure to carcinogens. The group of 12 substances including 9 agrochemicals i.e. aldrin, chlordane, DDT, dieldrin, endrin, mirex, heptachlor (HCH), hexachlorobenzene (HCB), toxaphene; and industrial substances viz polychlorinated biphenyls [PCBs], dioxin, and furans; is known as the Dirty Dozen.

They have been detected in human tissues, animal samples and aquatic species often in higher concentrations. Vulnerable pregnant women and young children are prone to adverse health impacts even at low level exposures. The developing countries and high risk groups share their major burden. Today, these have been measured in food supplies, in ecosystems, including human, fish, dairy products and wildlife populations in most regions of the world.

These substances result from, human activities and include industrial and household chemicals, fertilizers, and pesticides contained in products and in wastes. They also include unintentionally produced byproducts of industrial processes or incineration, like dioxins. They last for long in the environment, travel long distances on wind and water currents, bio-accumulate in human and animal tissue and have significant harmful impacts on human health and the environment, even at low concentrations.

‘Organic’, means production of fruits, vegetables and food-grains with no use of pesticides or inorganic fertilizers. But in the context of POPs it means the carbon based products. The synthetic chemicals, developed to control disease, to combat insect pests, and to provide comfort and convenience in daily life, cause a serious damage to the health of wildlife and people. Severity of the problem has forced the international community to negotiate a global treaty for successful, safe, viable and sustainable alternatives to POPs.

POPs are, thus, carbon based chemical substances with common properties: Anthropogenic or Toxicity, Persistence, Bio-accumulation, Potential for long-range environmental Transport. These resist the natural processes of degradation, have long life and do not easily or quickly break down in air, water, soil, sediments and/or biota. They readily absorb in fatty tissue and accumulate in the body fat of living organisms; and move up the food chain, especially into larger, longer-living organisms. Being fat soluble, they bio-magnify in the food chain and accumulate in the tissues. They are transported in the atmosphere in steps or hops via the ‘grasshoppers’ effect’, with alternate phases of volatization and condensation. They are also transported by migratory organisms. Transported in the environment in low concentrations with fresh and marine waters, these result in wide-spread distribution across the earth, exposing both humans and environmental organisms. POPs such as PCBs, DDT and dioxins can be found in areas far from their source. Dioxins and furans, unintentionally produced by processes such as incineration, released anywhere can cause harm to the people thousands of miles away.

Transported via convection currents to colder regions, the Himalayas could be a major sink for POPs to enter the ecosystems through rivers. The Arctic, Antarctic and mountain areas represent the ultimate fate of these chemicals. Contamination has been found around the Udhagamandalam plant of Hindustan Insecticides Ltd where DDT was manufactured. Even the area around Bhopal plant is contaminated. Now we’re just finding them everywhere. Pesticides end up in the food chain, water and air. They have been found in fish from all the lakes and in sediments.

These can get into the ecosystem during production, transport, storage and application. In the fresh water systems they enter the food chain through fish reared in contaminated water bodies. Rivers take the POPs to the marine environment in the oceans and seas. Sea gets them due to direct discharges, ship traffic, ship scrapping and through the atmosphere.

They concentrate in living organisms through the process of “bio-accumulation” and magnify through “bio-magnification”. Fish, predatory birds, mammals and humans, being high up in the food chain, absorb the greatest concentrations. Health impacts are most acute in populations consuming large amounts of fish, like fishermen. Children are specifically vulnerable to environmental hazards, more than adults.

Now, all 12 of the dirty dozen contaminants have been detected at significant levels in the Arctic. Inuit mother in Canadian region has five times as much dioxin as that of her counterpart in the industrialized world. Most polar bears die before their first birthday. As early as 1970, Canadian and European scientists discovered that DDT and PCBs were showing up in seals in the far north. Some of the bears have female and partial male genitalia. Sex steroid hormones being essential for reproduction and important for sexual behavior, are the most vulnerable endocrine variable influenced by POPs.

Pollutants are classified as ‘persistent’ because they are not degraded easily in the environment by physical, chemical or biological processes. With bio-magnification, they constitute a serious environmental hazard with long-term risks to individual species, to ecosystems and to human health. Most POPs generated in one country can affect people and wildlife far from where they are used and released. Unlike developed nations many of developing nations have only recently begun to regulate them.

Humans are exposed to dioxins and furans through their diet, mainly through fats and animal foods. Long-term exposure affects bone marrow, decreases red blood cells, anemia and the immune system. In the waterways, POPs travel long range, accumulate in human and animal tissues, magnify in food chains and significantly impact human health and environment. Many POPs had unforeseen effects on human health and the environment.

Perhaps the most infamous of the POPs, ‘Dichloro-dephenyl-trichloro-ethane, DDT was first synthesized by a German chemist in 1874. It was hailed as a means to stamp out insect-borne disease helping the farmers in winning the war against crop destroyers overnight. The discoverer, Paul Muller of Switzerland, won the Nobel Prize’. DDT was widely used during World War II to protect soldiers and civilians from malaria, typhus, and other diseases spread by insects. Once in the body it is stored in organs rich in fatty substances such as adrenals, testes, or thyroid. Because the small amounts of pesticides are cumulatively stored and only slowly excreted, the threat of chronic poisoning and degenerative changes of the liver and other organs is very real. After the war, it continued to be used to control disease and agriculture. It continues to be applied in several countries to control malaria. The long-term exposures have been associated with chronic health effects. DDT has been detected in breast milk. DDT once a widely used pesticide has been banned from use in most western countries. Its exposure was brought to public attention by Rachel Carson in her book, ‘Silent Spring’.

The primary means of human exposure include, exposure to DDT dust and vapor from fumigated fields and forests; contact with mothproofing products; and ingestion of fruits and vegetables treated DDT-containing pesticide. In mammals, DDT and its major metabolite, DDE, persist in the body and are stored in fat tissue. They can cross the placenta, potentially interfering with fetal development. DDT has been detected in the blood of people from Himachal Pradesh despite the fact it is not used there for malaria control, re-emphasizing the need to study the colder climes from a POPs perspective and also their possible illegal use in agriculture.

Dioxin was the unwanted byproduct of Agent Orange, the code name of herbicide developed for military use to destroy covering vegetation in Vietnam to protect American and allied troops from ambush or other unprotected movement of the enemy. A class action suit filed on behalf of the veterans in 1979 against the chemical companies was settled out of court leading to setting up of a settlement fund. Symptoms of exposure include nerve and liver damage, weakness and pain in the hands and feet, and fetal abnormalities and miscarriages. Trace amounts of dioxins have been found as contaminants in incinerator smoke, automotive exhaust, cigar and cigarette smoke and where combustion of aromatic hydrocarbons has taken place.

Though some of the POPs have never been used or manufactured in India, they are reported in various studies showing that they did find their way into the country. This could be due to imports. New PCB sources include the massive ship breaking activity at Alang (Gujarat, India) and at other places like Bangladesh and Pakistan where 90% of the world’s thirty-year-or-older ships are broken. Rivers in India, like elsewhere, are contaminated with pollutants due to various types of discharges.

Waste incineration has been identified as a major source for unintentional POPs internationally. Other major emitters are pulp and paper industry, coal based thermal power plants, cement kilns, etc. Many still use polluting processes and do not promote clean technologies. Dumping of medical waste is deadly and need proper incineration based on proper segregation. Municipal Solid Waste is source of many polluters. In India it is about 50 million tons annually. Bio medical waste produces dioxins and furans on unregulated incineration. Mercury from broken thermometers is very dangerous. Disposable syringes are also a source of toxics. E-waste is a growing problem in the developing world.

Destitute rag-pickers face exposure to toxic chemicals in the broken equipments. Workers also get exposed to carcinogenic compounds called dioxins that are by-products of incinerated plastics.

Waterways are polluted due to flush of wastes of all kinds into them. Even the chemical sprays of crops, gardens, forests and fields lands in the waterways due to soil erosion. Pesticides are everywhere in waterways as they pervade the environment. The groundwater is always on the move at varying speeds to pollute water several miles away from the place where the pesticide was used.

WTC collapses and fires constituted a new type of pollution source, with ashes in nearby areas consisting of asbestos, fibreglass and concrete dusts. As a solid waste incinerator, it became asbestos factory of enormous size; a volcano of hot gases and dust cloud generating many toxic, carcinogenic and irritating pollutants. It exceeded all types of emission standards. Toxic and carcinogenic pollutants in the air were generated continuously by fires as by-products of incomplete combustion. There were thousands of tons of asbestos, fibreglass, silica and alkaline concrete, heavy metals, PCBs and acids as the latex paints contain mercury, lead from car batteries, and leaded glass of computer screens. There were also products like paper, cardboard, wood and plastic, furniture, floor carvings, and textile partitions to aggravate the fire. Jet fuel provided the heat for burning. All this produced dioxins, furans and other toxins. The consequences of this pollution had to be borne by those working on the pile, others caught in the initial horrendous dust cloud, those living or working in the area, those who cleaned apartments, those at risk like children, elderly etc and those who handled the disposed debris in India, and Korea without protection or without knowledge of the contents.

Industrial and non-industrial processes, involving high temperatures, release POP unintentionally, including Dioxins, Furans, PCBs and HCBs into the environment. Open burning of waste and dead bodies is other source of dioxins and furans. The combustion processes, power generation and metallurgical processes lead to releases of dioxins in the air. Paper and Pulp industry is the other source of dioxins and furans apart from PCBs and HCBs. Indian paper mills continue to use elemental chlorine for production of bleached grades of papers for economic reasons. Iron and steel sector is a major contributor of dioxins and furans releases.

In the thermal plants, the coal causes release of dioxins and furans due to high temperature combustions. Cement companies also use coal as fuel in cement kilns. Chemical industries use chlorine as part of manufacturing process. Chlorinated aromatics and vinyl chloride manufacture release dioxins and furans. Manufacturing of pesticides, chlorinated paraffin wax, and vinyl sulphone and dinitro cresol also results in dioxin and furan releases. POPs are released into waste water in production of drugs, dyes and pesticides.

National defence is one of the largest producers of hazardous wastes. The stockpiling of nuclear weapons, the use of chemical warfare, unexploded landmines and other ordnance are all environmental hazards. The wars generate hazardous wastes, contamination of air, water and soil and destruction of numerous natural and cultural resources. The wastes are dumped in the landfills, injected into wells, burned in open air, left in corroded and leaking containers. The defence forces are the biggest landlords. During war, the military uses millions of gallons of fuel just to move the lines nearer to the border in preparation for the ground campaign. The extensive air campaign uses an enormous amount of jet fuel. The campaign in 1991 spilled 58 times the oil spilled from the Exxon Valdez in Prince William Sound.

The stockpiles of the weapons, thousands of tones, remain for disposal. Unexploded landmines of the World Wars still exist in Europe. Several landmines used in Iraq wars were shipped to India. There is also a problem of solid waste disposal including millions of used bags, vast amount of military debris of bombed-out tanks, cars and buildings, plastic water containers, mail and packages. There is large number of graves dug to dispose of the dead bodies in plastic bags manufactured from oil. Siachen area has turned into world’s highest waste dumping ground by stationing thousands of soldiers for decades now. Over 20,000 tones of waste, in the form of aluminium tins, artillery shells, fuel containers, batteries and the like, has accumulated in the cold desert environment there.

Little was known about the harmful effects of POPs until the 1960’s. Now, there is evidence to prove a range of injuries to human health and the environment. A range of health injuries in birds, fish and mammals also proved this. Wildlife injuries include reproductive failure and population declines; abnormally functioning thyroids and other hormone system dysfunctions; feminization of males and masculinisation of females; compromised immune systems; behavioural abnormalities; tumours and cancers; and gross birth defects. POPs and other man-made toxic chemicals are present in the bodies of people.

Human exposure to POPs is linked to cancers and tumours; neurobehavioral impairment, reduced performance on standard tests and changes in temperament and immune systems; reproductive and sex-linked disorders; shortened period of lactation in mothers; and diseases such as chronic gynaecological disorder, increased incidence of diabetes, etc. Learning and behaviour disorders in children and adolescents have been linked to pre-natal exposure, which also contributes to immune system, reproductive and sex-linked disorders and deficits that may appear later in life. Foetuses are highly vulnerable to industrial toxins, organic solvents, mercury, pesticides, alcohol, tobacco, cocaine, and heroin. Infants continue their exposure in their mother’s milk.

Most chemicals in modern use have simply not been tested for their impacts on human health, even very basic effects. Even tests usually are far too simplistic to anticipate many important health effects. Chemicals do not get recycled. They just bio-accumulate. Use of pesticides gives them higher yield but is dangerous.

Human beings can be exposed to POPs either intentionally or unintentionally. The water streams contain unintentionally released POPs like PCBs. Convection currents carry them to colder regions, like Himalayas, to persist for longer periods and to re-enter the ecosystem through rivers. Marine contamination occurs due to outflows of rivers into the oceans, direct discharges into the sea, ship traffic, ship scrapping and through the atmosphere. The high levels of DDT at Nainital lake suggest the illegal use of DDT for agriculture. A toxic dumping ground exposes the unskilled workers to death. Degenerative diseases of bones and joints cripple teenagers; premature graying frosts of hair of children. The children are born with deformed body parts. One also finds a large number of youth having gray hair, severe joint pain and spinal problems. Exposed families have one ailment or the other; heart ailments, paralysis, skin problems, asthma and arthritis etc.

People have been poisoned by deadly industrial gases in Bhopal in India and toxic land-dumps in Love Canal in United States. Due to intensive use of defoliants, herbicides and other chemicals by US forces in Vietnam led to highest rate of spontaneous abortions in women, and high incidence of vaginal infections, cervical cancers, and occurrences of birth defects in their offspring. Tens of thousands of workers in glass factories in Firozabad, India face exposure of excessive heat, noise, accidental burns, and cuts and lacerations caused by broken glass. Tannery workers are exposed to diseases like tuberculosis, asthma due to workplace exposures and conditions.

Many of the chemicals accumulate faster in the fatty cells of the body. Mothers have had many years of exposures. When pregnant, these stored toxins can affect the embryo in a number of ways. Dioxin is one toxin that crosses the placenta with ease. It is also stored in the father’s fatty tissues. This is what made Agent Orange such a nightmare for Vietnam vets and their offspring. Its legacy still continues in the United States’ veterans and Vietnamese citizens.

There has been steady rise in chemical accident frequency since 1900. Most of the causalities involved the people directly handling the chemicals i.e. occupational exposures and the local residents. Deaths and injuries have declined over the years. But potential for harm has increased due to increased toxicity of substances as measured by the number of evacuations that occurred over time.

In India, Bhopal has been identified as a hotspot for certain POPs. Numerous POPs including HCBs and PCBs have been found in Gujarat Industrial Estates. DDT and its metabolites, endosulfan have been found at the site of Hindustan Insecticides Ltd Kochi, and Udyogamandalam pesticide production facility. In Punjab, some villages suffer from a variety of cancerous ailments due to unmonitored use of pesticides in agriculture. Test report show genetic damage, high rate of miscarriages among women and slow growth in children. High concentration of mercury, copper, cadmium, chromium and lead in drinking water has been found and the food chain. Pesticides have been detected in vegetables, blood as well as human and cattle milk. Gastrointestinal, skin, eye, dental and bone problems are significantly higher in these areas than villages in proximity of drains. Fish were reported to be dead in the canals due to sewage and heavily contaminated and untreated industrial waste being drained into the rivers. Toxic clouds produced deadly results in Bhopal in 1984.

The Exxon Valdez Incident, 1989 involved the super tanker Valdez, operated by US organization Exxon Mobil Corp. It ran on a reef in Prince William Sound, Alaska, due to human error and spilled 11 million gallons of crude oil. In 1991, during the Gulf War, the Iraqi bombing of Sea Island terminals led to millions of gallons of oil spill. This was many times the size of the Exxon Valdez. It severely depleted the 113 species of birds that migrate from Africa to Eurasia spending the winter in the Gulf. About one million tons of crude oil was lost to the environment. It damaged life in the Persian Gulf considerably, poisoned water, killed thousands of seabirds and caused severe damage to local marine flora and fauna.

Hooker Chemical and Plastic Corporation dumped chemical wastes into the area around the city of New York. Love Canal, a neighbourhood in Niagara, was used as a dumping-ground for toxins. During 1942 to 1953 the company had dumped about 20,000 tons of chemical waste into the disused canal. In 1958, three children suffered chemical burns from seeping toxins. Blood samples of residents showed the high count of white blood cells which could lead to leukaemia and liver damage. There are several other instances of waste dumping in the developing countries.

Dealing with DDT worldwide is a dilemma. It is the target of complete elimination across the world. But thousands of tons of DDT are required every year for malaria control. Between 300 and 500 million people a year are sticken with malaria. Up to 3 million of them die from it. DDT reduction needs to be conducted carefully so as to balance the public health benefits of the pesticide against its toxicological effects in non target mechanisms.

In India, problem of hazardous substances became prominent after Shriram Gas Leak and the Bhopal disaster. It led to intensive judicial intervention and much legislation. But if the legislation alone could solve the environmental problems, India could be the safest place. Key is the implementation of the laws and strenuous efforts to deal with the menace of hazardous wastes, toxic chemicals and pesticides. There is still widespread lack of awareness and it is still widely believed that chemicals are innocent until proven guilty. Powerful chemical industry, with trillions of dollars of annual turnover, has strong clout with the governments. It compounds the problem manifold. POPs are the culprits in damaging the health and environment of the present and the future generations. Solution lies in precaution and prevention and making the polluters pay for their misdeeds.