the womb is, in essence, a miniature universe in creation. Primitive cells and tissues take human form within its sheltered confines. Sheltered? Not so anymore. This placid abode of the yet unborn is under siege. Crossing the physical barrier between a mother and her foetus, noxious environmental pollutants generated by modern agricultural and industrial practices are playing havoc with the growth of the latter.
The foetus, the developing child in the womb, is a sensory responsive living entity acutely perceptive of its environment, which, in turn, determines its fate. The conception and nurturing of the child inside the womb is, therefore, a highly critical process. Any exposure of the mother to environmental hazards costs the developing baby a healthy growth, even if it survives these onslaughts.
"There is no safe womb today," an un report on environmental degradation and its impact on women and children, prepared before the Rio Earth Summit (1992), had declared. Another study by the United Nations Environment Programme (unep) reports that the foetus is sometimes drastically affected by pollutants, even if the mother remains untouched by them. But buried as it is deep inside its mother"s uterus, how is the foetus exposed to teratogens (substances that cause structural damage to it)?
"Most toxic substances reach the foetus by crossing the placenta, the structure separating it from the mother"s blood circulation. It is made up of thousands of blood vessels that filter substances between mother and foetus during pregnancy. Some pollutants pass through the filter because they are similar in chemical structure and weight to nutrients that the foetus needs," explains Madhu Roy, a gynaecologist at New Delhi"s Apollo Hospital.
Pregnancy problems Though a woman is as susceptible to pollutants as any other adult, a pregnant woman"s changed physiology makes her a more vulnerable receptor. Increased blood volume and body fat, coupled with a faster breathing rate, go hand in hand with pregnancy. This results in more absorption and distribution of toxins and gases. To top it all, placental processing of intruding substances may enhance the teratogenic effects of these agents.
Besides this disguised intrusion, sexual intercourse during pregnancy could provide another route for exposure. Studies reveal that toxic substances in the semen of a male could be absorbed in the mother"s bloodstream through the vaginal wall, which could then reach the foetus. Although a lesser threat, this factor, nevertheless, has to be borne in mind.
In general, pollutants and toxins affect both sexes similarly, but finally, it is the maternal exposure that can be damaging to the foetus, directly or via genetic processes occurring before or at fertilisation. Mediated through either parent, the outcome of these exposures can be disastrous. The impact of teratogens can vary from spontaneous abortions, where the foetus succumbs to attacks at a very early stage, to stillbirth, where the child is born dead, and neonatal death, where the child dies soon after birth. These are the results of severe interferences. In less severe cases, where the foetus manages to survive, there can still be premature delivery, birth defects, low birthweight, or developmental and behavioural defects. These may not become evident until a few years after birth, for instance, reduced fertility which becomes apparent only at the time of reproduction.
According to the World Health Organization (who), the frequency of spontaneous abortions in humans ranges between 14 per cent and 30 per cent of all pregnancies. Foetal losses occur mostly in the early weeks of pregnancy with their frequency decreasing considerably after the first three months (the first trimester). Two who studies conducted in 1975 and 1977, reported in the Organization"s Report on Women and Occupational Health Risks, 1982, that of all aborted foetuses, chromosomal anomalies are about 60 to 100 times more frequent in spontaneous abortions than in live births. Which means that a high proportion of spontaneous abortions are due to genetic abnormalities in the foetus arising from environmental factors. Further, who figures put the incidence of birth defects at two-six per cent of all living children worldwide.
"Rapid industrialisation, unsafe working environments, improper installation and incorrect handling of mechanical devices generating electromagnetic waves at home and exposure to cooking fuel has resulted in escalating environmental pollution and deterioration in the quality of indoor air. This exposes the foetus to many known and unknown pollutants with recognised or hitherto undocumented harmful effects," sums up M A Faridi, a paediatrician at the Guru Tegh Bahadur Hospital, New Delhi. Foetuses bear the brunt of environmental degradation globally, with those in developing countries suffering the most.
Toxic chemicals, lethal gases, deadly viruses and hazardous radiations wreck foetuses. Apart from the nature, dose and duration of exposure to the toxic agent, the outcome depends on the developmental stage at which the exposure occurs. "Exposures occurring during the critical period of embryogenesis, that is, the first two months when the foetus is undergoing organ formation, usually lead to severe structural abnormalities, often resulting in death. If the exposure occurs later, functional deficits and growth retardation are the likely results," explains Madhu Roy.
The worst of the toxins is lead. Towards the end of the 19th century, unusually high rates of infertility, spontaneous abortions and birth defects in newborns were reported in women exposed to lead at workplaces in many parts of Europe. This was reported in the unep Report on Children and the Environment, 1990 .
Today, the chances of exposure to lead have increased manifold. Widely used in batteries and glass, pottery and pharmaceutical manufacturing plants, lead fumes are emitted by metal smelters, usually operated in small workshops in congested areas. Ingestion of dust contaminated with lead and inhalation of fumes emitted by lead-based paints are other menaces. Studies by obstetricians and gynaecologists such as Sheldon H Cherry of the Mount Sinai Hospital and Irwin R Merkatz of the Albert Einstein College of Medicine (both in New York), have indicated that iron and calcium deficiencies, which often occur during pregnancy, increase a tendency towards lead toxicity in women. Under high levels of exposure, foetuses are aborted; if they survive the attack, they are left with birth defects like mental retardation and convulsions.
There is scientific evidence (presented in a 1992 who study) that points to the fact that lead harms male reproductive capacity as well. By damaging male germ-cells, it leads to abortions and birth defects in foetuses of their unexposed partners. Paternal exposure to lead also results in increased rates of subsequent cancers in the offsprings.
Another chemical, cadmium, damages foetuses by disrupting essential nutrient supply through the placenta. Discharged into sewage systems by electroplating factories, and into the air by deteriorating rubber tyres, cadmium - an active component of cigarette smoke - has a special affinity for the placenta. It interferes with the transportation of essential nutrients to the foetus. The result is severe growth retardation, foetal malformations, foetal death and anaemia in the newborn. Studies reveal that cadmium butts into the calcium metabolism in the foetus, leading to multiple skeletal defects and abnormal bone formations. Moreover, due to increased sensitivity of the nervous system to cadmium, brain abnormalities follow.
Though acute mercury poisoning is rare today, long-term exposure to low levels of mercury are more common. Recent studies (the unep Report mentions one study conducted in 1988) reveal a close correlation between mercury in the blood cells of mothers and newborns. But the babies have been found to have even higher levels of mercury than their mothers - 47 per cent higher, on an average. Pregnant women, and thus, foetuses, are exposed to mercury through contaminated fish, units manufacturing electrical appliances, paints, ceramics, neon lights and thermometers. High concentrations of mercury vapour have also been found in dental clinics.
A classic contamination case of a chemical that can affect the foetus without harming the mother was the epidemic of methyl mercury poisoning through seafood in Minamata, Japan, in 1956. The contamination was due to mercury-containing effluents discharged by nearby industries. Later, it was noticed that six per cent of the children born over a 10-year period in this area had cerebral palsy (Minamata disease), while mothers remained unsymptomatic. Nervous system tumours, mental retardation, deafness, blindness and irritability were found in the newborns. Similar findings were reported in 1956 and 1960 in Iraqi children, whose mothers, while pregnant, had eaten grain treated with methyl mercury, a fungicide. In 1990, a who report, based on the Minamata and Iraqi studies, cautioned that foetuses were especially vulnerable to mercury toxicity.
The pesticide bit
Used largely in the agricultural sector, pesticides sneak into food, water, air, and eventually into the foetus. Their destructiveness is aggravated by their long staying power in the environment and inside body fat. This is enough to put a growing foetus into their clutches; the rate and range of adverse effects like stillbirths, spontaneous abortions, premature births, and birth defects like facial mutilations, including cleft lip and palate, are very high in those exposed.
Although many organo-chlorine pesticides were banned in the West in the "60s, they are still very much conspicuous by their presence. The current levels of use of ddt in developing countries exceeds the past levels of its use in the developed world. Pesticides like ddt, dbcp (dibromochloroprane), lindane, dieldrin and heptachlor are proven teratogens. Offspring of women exposed to ddt during pregnancies have been found to have thrice as much concentrations of dde (a metabolite of ddt) in blood samples than those unexposed.
Significantly, while female workers exposed to pesticides are naturally inclined to expose their unborns to the toxic effects, studies have proved that partners of male workers are not spared either. For instance, a who study conducted in 1990 on workers in floriculture in Colombia, usa, showed an increased rate of birth defects, spontaneous abortions and premature deliveries among female workers as well as unemployed wives of male workers.
The Aral Sea region in Uzbekistan offers a mute testimony to the sinister effects of pesticides and that of unplanned, unsustainable economic growth. In the erstwhile Soviet Union, the mandarins of power had decided to initiate intensive cotton plantation, purely due to the crop"s high cash value. The massive use of pesticides in cotton plantations killed the Aral Sea; its dry chest today carries the skeletons of abandoned ships, and the entire region is burdened with toxic dust and poisoned water.
Here, people are exposed to very high levels of toxins. With pregnant women and foetuses more susceptible to toxins, the resultant level of sick newborns is 87 per cent; 85 per cent are born with asphyxia (breathing difficulties; in acute cases death may occur - a condition called Asphyxia neonatorum). Every ninth newborn has a dysfunctional thyroid. Brain damage and genetic and endocrinological diseases are common in newborns. "We have found high levels of heavy metals like manganese, lead, strontium and other elements in the placenta and blood," says Oral Ataniyazova, a Nukus (Uzbekistan)-based gynaecologist and obstetrician (Down To Earth , Vol 4, No 12). Unusually big newborns and anaemic pregnant women with huge, distended placentas are also reported from the region.
The cause of these phenomena is yet unknown. While some believe it to be acute maternal anaemia (reportedly, there has been a five-fold increase in the incidence of anaemia in the region between 1982 and 1992), Ataniyazova and her colleagues hold that this is due to toxins.
Polychlorinated biphenyl (pcb) is a chemical that retards the growth of the foetus through nerve and developmental impairment. Used in transformers and electrical capacitators, pcbs are ubiquitous in the environment because of indiscriminate dumping, over the years, in unregulated landfills. Resistant to biodegradation, pcbs enter the food chain and accumulate in fat depots in the body. Disposal and leakage of industrial fluids into rivers and coastal waters contaminate fish, making it a primary dietary source of pcbs.
Evidence of this was found in 1968 when pregnant women in Japan, who had consumed oil contaminated with pcb s that leaked from a heat exchanger, gave birth to infants who suffered retarded growth. Called "Yusho" disease, the ailment"s victims suffered from dark brown pigmentation on their skin and mucosa for six months after birth. Seventeen per cent had retarded growth and most had dental abnormalities, skull deformities and delayed bone maturation. Another study found increased incidences of birth defects and low birthweight in mothers who consumed fish contaminated with pcbs.
Behind closed doors
In rural communities of developing countries, emissions from biomass fuels in poorly ventilated rooms contaminate the indoor environment (Down To Earth , Vol 5, No 4). Used by about half the world"s population, this source of domestic energy, often the only one, emits pollutants harmful to the baby growing inside the exposed mother.
Studies, though few, show that these women can be exposed to more carbon monoxide (co) and benzopyrene than chain smokers or people working in highly polluted cities. The type of wood burned and the design of the fireplace also determine the extent of pollution. One study says that a woman working in such conditions inhales fumes that amount to smoking 100 cigarettes daily! Given the fixed role of women as home-runners, pregnant women cannot help spending a great deal of time in the kitchen; the impact is borne by the foetus.
Even as many people in developing nations make their first moves up the fuel ladder from biomass fuels to kerosene and liquid petroleum gas (lpg), health risks for the growing foetus persist without adequate control of emissions and proper ventilation. In urban areas, for instance, simply changing the medium of cooking does not ensure a safe kitchen environment. A who study in India by B Bahera et al breaks the myth that lpg as an energy source lowers levels of toxic gases in urban homes. The study found same levels of co using three separate mediums of cooking: lpg, kerosene and wood.
co denies the foetus its life-supporting oxygen. Abnormally high levels of co are found in heavy traffic areas in urban centres. Cigarette smoking, both active and passive, further exposes pregnant women to co.Though fresh air contains extremely small amounts of co - about 0.1 to 0.5 parts per million (ppm) - in urban centres these levels rise to mean concentrations of three to 10 ppm, and can be as high as 50 ppm in heavily industrialised areas. This considerably reduces the availability of oxygen to the foetus, thereby suffocating it.
co diffuses across the placenta and binds with foetal blood. The affinity of haemoglobin, the component of blood that transports oxygen, for binding co is about 200 times more than it is for oxygen. Interestingly, co concentration in the foetus generally exceeds that in the mother by 10 to 15 per cent, and persists for a longer period in the foetus than in the mother. When foetal carboxyhaemoglobin ( co and haemoglobin complex, cob h) levels rise, oxygen levels in the foetal blood drop, affecting the brain, heart and adrenals. The outcome may be severe brain damage or foetal death. Partners of men exposed occupationally to exhaust and machine fumes and, thus, to high levels of co , have also shown increased rates of spontaneous abortions.
Acute oxygen shortage can have another tragic outcome: the foetus may pass stool (meconium) which is otherwise an after-birth phenomenon. Faridi says that meconium may get into the mouth of the foetus and may be inhaled into the lungs, either inside the womb or just after birth, when it gets the first direct whiff of air. The result in either case can be disastrous for the baby. From inflation of lung tissue inside the womb to pneumonia, obstruction of the windpipe and unequal distribution of oxygen in the lung tissues in a new-born, the effects are serious indeed.
In the light of these facts, not only our coming generations, but even their conception, seem to be faced with a completely uncertain future. A polluted environment can actually take away the basic instinct for mating. Studies have revealed that exposure to high levels of metals like lead and manganese lowers sexual urge in men and causes impotency by interfering with the nerves of the male reproductive system. Even if the sexual act is accomplished, chemicals prevalent in the environment may spike conception by disturbing the delicate hormone system, or have a direct toxic effect on the foetal germ-cells (the egg and sperm). Recent years have seen a decline in fertility rates in men and women the world over, and it is estimated that one in every six couples has trouble conceiving.
According to some investigators, sperm counts have declined by about a third in the past 20 years (at a rate of 2.1 per cent every year). The quality of sperm has declined as well, a higher percentage of it being reported as deformed and/or non-functional. There is an increase in the number of testicular cancer cases, and of boys born with reproductive abnormalities like undescended testicles. Experiments on animals have shown hormonal derangements that produce masculinised females and feminised males due to chemicals masquerading as sex hormones and - aptly named - endocrine disrupters.
Described in the recently published book, Our Stolen Future , by Theo Colborn and others, endocrine disrupters (61 synthetic chemicals have been identified as such) mimic sex hormones in behaviour and disrupt the functioning of reproductive hormones, estrogen and androgen. Popularly called the "gender benders", these chemicals can fit into hormone receptors, turning on cellular processes which, in fact, should not be turned on. Or they may simply block the receptors, preventing the real hormones from getting through. Besides affecting fertility of adults, this type of intrusion can be disastrous for the foetus. Infinitesimal concentrations of an endocrine disrupter hitting the foetus at the wrong moment of its unfolding can derail development, change the sex or sexuality of the unborn child, and affect its future fertility.
There is no escape from these chemicals; soap, ink, adhesives, cosmetics, electric equipment... they are present in the most basic elements of modern-day living. A partial list of these suspect chemicals include:
l phthalates, which are added to plastics for flexibility and are also present in paints, inks, adhesives, plumbing pipes, paper and cardboard used in food packaging
l alkylphenols, which are products of the microbial breakdown of certain ingredients in detergents, paints, herbicides and cosmetics
l organochlorine pesticides, including ddt , aldrin and dieldrin
l polychlorinated biphenyls ( pcb s), found in electric transformers
l dioxin, a byproduct of combustion
l vincozolin, a common fungicide
Scientists often say that, comparatively, India"s per capita consumption of such chemicals is low. However, it has been pointed out that while consumption may be low, exposure persists from both the high level of pesticide residue in our foods and the poor quality of water. Despite the low per capita usage of pesticides in agriculture, the world"s highest level of ddt in body fat is evident in Delhi residents. High levels of pesticides have been found even in mother"s milk in India.
Obnoxious environmental factors may even cause mutations. "A mutation of the egg and sperm may result in the death of an embryo, causing a miscarriage or stillbirth, a birth defect that may or may not be apparent right away, or a genetic defect that does not show up until several generations later," explains Faridi.
Children born much after the world"s worst industrial tragedy in Bhopal are showing signs of this; born to parents exposed to methyl isocyanate ( mic ) in the 1984 gas tragedy, many are found to have holes in their hearts. "Medical experiments elsewhere in the world have conclusively proved that effects of such disasters continue to be felt for many years. Even after many generations, the effects of the Hiroshima atomic blast are being noticed in children there," says Hariharan, a cardiologist at New Delhi"s Apollo Hospital, who has examined these children.
Clean environment: a birthright
The 1989 un Convention on the Rights of the Child acknowledges that a child"s well-being depends in part on events before birth. This means that foetuses (and their mothers) need protection.
Despite the recognition of the heightened sensitivity of the foetus to environmental hazards, India has no well-defined safety standards and exposure limits for pregnant women, with the foetus as primary concern. Most established standards are intended to prevent acute toxicity in exposed workers or those at risk. Thus, even though complying with available standards may protect pregnant women from adverse sequels, their foetuses may still be vulnerable and at risk.
"Answers to questions about safe reproduction must come partly from scientific information and partly from political considerations," points out Harsh Jaitly of the New Delhi-based Society for Participatory Research in Asia. Unfortunately, there is little scientific research into these issues. Policy decisions also languish from ambivalence about a woman"s "proper role".
Since the quality of life - the physical and social surroundings - of a pregnant woman influence the development of the foetus, recognition of her rights over her body, reproduction and to social advancement would place a sound foundation for future generations. This would involve a campaign for mechanisms that empower women, especially for better health and education services. Today, women and their children are generally the lowest beneficiaries of health services.
There is also a pressing need for the government to delve deep into the extent of damage that has already been done. Besides, protection for the woman and the foetus cannot be restricted to guarding the pregnant woman. Since exposed males have the same impact on the foetus, the basic need is to ensure a clean environment. And this calls for wide-ranging policy changes in industrial laws, on the use of certain substances, in trade and introduction of an omnibus health policy. The threat to the foetus from environmental degradation is actually a direct threat to future generations. After all, if the mother"s milk turns into poison, the future is bleak indeed.
- Order of the Calcutta High Court regarding public opposition to a solid waste management plant, Bongaon, North 24 Parganas, West Bengal, 28/08/2023
- Kolkata: This year, 80% had deadly dengue-II
- 'Specially-bred mosquitoes help prevent dengue outbreaks'
- Counties on high alert as Rift Valley Fever kills 13
- Mumbai sees six dengue cases after first spell of monsoon
- Nipah scare: These are three biggest virus outbreaks that have killed hundreds in India