BODY BURDEN
Chemical Body Load
Chemical Body Load
Endocrine Disrupting Substances |
Childrens Health |
CHEMICAL BODY LOAD
Chemical Body Burdens and the Increase in the Production of Synthetic Chemicals.
The world production of organic (carbon based) chemicals has increased from about 1 million tonnes/year in 1930s to 7 million tonnes/year in 1950, 63 million tonnes in 1970 and 250 million tonnes/year in 1985. It has been estimated that the annual production of organic chemicals will double every 7-8 years.
Many manmade chemicals are fat soluble and not readily broken down by metabolic processes, and because of this, can be stored in body fats and build up to dangerous levels. Predator birds, reptiles and mammals, including man, are particularly at risk, because persistent organic contaminants, along with some heavy metals, can build up in the food chain (bioaccumulate). Many are then passed on to offspring, either via the egg or via the placenta, at a particularly sensitive stage of their development. Mammalian offspring are potentially most at risk because further exposure to the pollutants stored in body fats occurs during breast feeding.
Human exposure comes not only from the build up of environmental contaminants in the food chain and from exposure to contaminants in air and drinking water, but also from the direct ingestion of substances used in food packaging and in processed foods, and from the absorption through the skin of certain substances used in cosmetics.
The global expansion of the organic chemical industry has been phenomenal, with total production in the 1950s estimated at around 7 million tonnes, compared to over 250 million tonnes by the early 1990s (CEC,1992). Not only the sheer volume of chemicals used, but also the number of chemicals, have increased dramatically, with perhaps around 80,000 chemicals currently in widespread use. This rapid post-war expansion in the chemical industry has certainly resulted in increased foetal exposure to many lipophilic contaminants.
However, the problems associated with early-life exposure to pollutants are only now becoming a focus of attention. DDT a recognized persistent organic pollutant (POP) was first found in breast milk in 1950 while PCBs were detected some twenty years later.
Now, over 350 contaminants have been found in human breast milk. Despite this, mothers should certainly not be discouraged from breast feeding. The message is 'don't stop breast feeding, stop the POPs.' The priority focus must be the protection of breast milk from POPs and other persistent pollutants. Substances that are persistent and able to bioaccumulate must be phased-out irrespective of their known toxicity, because if effects due to these substances do become evident, then it will be too late.
Potential Effects Of Exposure
The potential effects of exposure to the chemicals, which are now found as contaminants in human body fat and breast milk are numerous. Some of the contaminants identified have the ability to cause cancer and some are able to impair the immune system.
Others, termed hormone disruptors or endocrine disrupting chemicals (EDCs), are known to interfere with the normal functioning of the bodies own hormones, or chemical messengers. For example, in utero exposure to sex hormone disrupting substances can compromise the ability of that offspring to reproduce later in life, while exposure to other hormone disrupting substances, such as thyroid hormone disruptors, can de-rail normal brain function. Animal experiments have shown that exposure to low doses of numerous environmental toxic agents, during the neonatal period of rapid brain growth (or brain growth spurt), can lead to disruption of adult brain function and increase the susceptibility to toxic agents in later life. In women, exposure has been implicated in endometriosis and increased breast cancer rates.
With regard to effects on the testes, there is epidemiological evidence linking certain occupational exposures with increased risk of testicular cancer and decreased sperm counts have been found in men exposed in the womb to the synthetic oestrogen DES (diethylstilboestrol), once used as a pharmaceutical medicament.
It is certainly a matter of increasing international concern that, in many industrialised countries, the incidence of hormone related cancers, such as breast cancer, prostate cancer, and testicular cancer, have all increased dramatically over the last 50 years. In the USA, childhood cancer rates also appear to be increasing at the rate of approximately 1% each year.
The following table from Chemical Trespass: A toxic legacy by Gwynne Lyons summarises some of the potential effects of exposure to endocrine disrupting chemicals.
Endocrine Disrupting Substances
SUMMARY OF THE POSSIBLE EFFECTS OF EXPOSURE TO ENDOCRINE DISRUPTING SUBSTANCES
(Taken from Health Council of the Netherlands,1997)
The possible effects of in utero exposure to endocrine disruptors include:-
- Abnormal development of the reproductive system, such as undescended
testes and defects (hypospadias and epispadias) of the penis. Feminisation
of the reproductive tract in males and masculinisation in females. Testicular
cancer, and clear-cell carcinoma of the cervix or vagina. Decrease in
sperm concentration and quality, and decrease in spermatogenesis.
- Abnormal development of the central nervous system, leading to neurological,
cognitive, and behavioural disorders (including effects on sexual behaviour),
smaller head size at birth.
- Other general developmental abnormalities, such as shorter pregnancies,
lower birth weight, disturbed hormonal regulation or thyroid gland effects,
arrested growth and effects on sex ratios.
The possible effects of exposure later in life include:-
- Abnormal functioning of the reproductive system, and disturbance of
hormonal regulation. In men, this could mean impotence and loss of libido,
reduced testes size and weight, decreased sperm quantity and quality
and altered spermatogenesis. In females, problems with breast feeding,
menstrual or menopausal problems, endometriosis, alteration in fertility
and an increased rate of abortions.
- An increased incidence of cancers related to hormonal disturbance, such as breast, endometrial, prostate, testicular, ovarian, adrenal and thyroid cancers.
In the late 1990s a new USA programme, called Body Burden 2000, was given the go-ahead. This initiative tested samples of blood and urine from the US population to measure the amounts of selected chemicals in people's bodies.
Children's Health and Chemicals
There is a growing acknowledgement that patterns of illness in children in the developed world drastically changed in the 20th Century. Many of the old infectious diseases are gone, only to be replaced by new chronic and disabling conditions that have been termed the 'new pediatric morbidity'. For example, asthma mortality has doubled, leukemia and brain cancer have increased in incidence, nervous system dysfunction including neurodevelopmental delay has significantly increased and the incidence of hypospadias (displaced urethral opening) has doubled. (Landrigan et al. 1998)
Some known and suspected causes are chemical toxins in the environment, poverty and inequitable access to medical care. Children are at risk of exposure to some 2,000 to 3,000 high production volume synthetic chemicals that have been developed in the last 50 - 60 years and are widely used in consumer products and the environment. Many of these chemicals are not tested for toxicity. More specifically, none are tested for their toxic impacts on children who are uniquely vulnerable to chemical toxins because of their disproportionately heavy exposures and inherent biological susceptibility. (Landrigan et al. 1998)
Children's unique vulnerability to chemicals
A number of factors contribute to the unique vulnerability of children to some chemicals. These include the child's individual biology, physiology and behaviour. Most systems of a foetus or child's body are immature and constantly developing. Depending on the state of that development and a variety of other factors, a child's detoxification systems and ability to excrete toxins differs from adults. While at times this can offer greater protection it can also increase vulnerability. Should the enzyme systems responsible for detoxification be damaged early in life, the result can be a lifetime of disabling chronic illness.
Children have a higher respiration and metabolic rate than adults. They eat and drink more per bodyweight than adults and their skin absorption may be higher. The higher skin absorption rate can result in a proportionally greater chemical dose. Children also spend more time outside than adults and their behaviour can increase their toxic load. They live life closer to the ground where contaminants often accumulate and put their hands in their mouths as part of their normal development. Being unaware of the risks, they are less able to protect themselves from exposures.
The timing of chemical exposures can be significant. Some studies suggest that early exposure to carcinogens can increase the risk of developing cancer if exposures begin early in childhood. Exposure to some chemicals and heavy metals in utero and early childhood can produce life long disabilities in neurological function and learning ability. Some substances can affect the endocrine system and result in developmental problems. (WHO 2003)
Researchers in the United States have linked some environmental exposures to specific diseases. The US Center for Disease Control (CDC) has established a public health tracking program to gather and analyse data about exposure to environmental health hazards and the health effects related to those exposures. They recently produced their second report on human exposures to environmental chemicals. (US CDC 2003)
Health Problems of Children associated with Chemical Body Burden
While the evidence and impacts of lead levels in children are well accepted, much less is known about the range of other chemical body residues. In a recent Australian study looking at the meconium (first bowel discharge) of new borns many synthetic chemicals were detected. These included lindane in 78% of samples, PCP 43%, Chlorpyrifos 59%, Malathion 34%, Chlordane 16%, DDT 52% and PCB in 27% of the 44 babies tested.
Health problems in children with high levels of chemicals in their bodies often commence at birth. These apparently normal infants were developing infections that required antibiotic treatment, or other problems that require medical intervention. Within the first weeks of life gastrointestinal problems can become apparent with the infant exhibiting feeding problems, gastroesophageal reflux, poor sleep patterns, skin rashes and/or eye infections. These can progress into recurrent infections of ears, respiratory tract and lungs, which cause problems such as poor sleep patterns, irritability, constant crying, failure to thrive, excessive activity levels and asthma. (Budd, L. 1995).
As the child grows, behavior can become a major problem, often accompanied by learning disorders. Depending on the severity of the problem, speech therapy and remedial teaching may be necessary to deal with the problem. Uncontrolled aggression may also be present. (Budd, L. 1995).
Fatigue, constant complaints of headache and abdominal pain become common, with repeated episodes of gastroenteritis dismissed as a virus, food poisoning or 'something eaten'. In some cases epilepsy may be present without any family history or other explanation for the disorder (Budd, L. 1995).
Quite often, children with behaviour and learning problems are not diagnosed and effectively treated. They are predisposed to becoming teenagers with behaviour problems, depression, bipolar or other psychiatric disorders. They can progress to become substance abusers, teenage suicides or go on to have a lifetime of psychiatric problems or some other disability. (Chapman, M. 2001)
For more information on persistent bioaccumulative toxins in children, see the discussion paper, Children's Environmental Health - Intergenerational Equity in action as a .pdf file or visit the factsheet section to download fliers on children's environmental health.
Children with chronic disease
The Australian Institute of Health and Welfare define childhood disability as 'a disability that restricts a child's ability to perform tasks associated with daily living'. In 2002, disabling chronic illness affected around 300,000 (7.5%) of our children. Of this 7.5% of children with disabling chronic illness, 54% had a physical disability and 46% had an intellectual, developmental or behavioural disability. At any given time, around 23% of Australian children are likely to have recent asthma while 10% have eczema and around 15% have emotional/behavioural problems. Some 0.5 - 1.0% of children have epilepsy, 60% of which begins in childhood. Around 2 children in 1000 have juvenile onset diabetes mellitus; and childhood cancer affects 14 per 100,000 children with a 75% survival rate. While technological advances have improved the survival rate for many children including low birthweight babies, around 15-20% of survivors have a major disability such as cerebral palsy, visual, auditory or intellectual impairment. At least half of the remainder have significant learning difficulties. (Isaacs & Sewell 2003) These figures are conservative as they only relate to hospital discharges. They do not account for individuals being treated by medical practitioners or natural therapists.
Chronic conditions put an increased stress on children and their families. They are at twice the risk of developing mental health disorders of healthy children and the risk increases if they have an accompanying disability. (Isaacs & Sewell 2003)
The social impact of disability and chronic ill health in the community is wide spread. An integrated approach to disability e.g. programs based on medical, social and disability models is essential to provide the best possible assistance for disabled children to maintain reasonable health and lead a normal life. However, without recognition of the cause of chronic illness and disability in our children, we cannot have the necessary interventions in place to improve their future.
Research and government initiatives are needed to protect child health
Children's health and chemicals is a growing area of concern. While the issue is attracting attention in the USA and within the World Health Organisation Intergovernmental Forum on Chemical Safety, still in many countries there are few initiatives to protect children from exposure to chemicals that can damage their health and ruin their lives.
Recommendation
Because of the special vulnerability of children to chemical exposures that can threaten their health and lead to a lifetime of disability and chronic illness, all Governments should initiate programs to:
References:
Budd, L. 1995. Children's health and chemicals. Toxic Playground: reducing the toxic chemical load on schools and childcare centres, Conference Proceedings. Total Environment Center
Chapman, M. 2001. Kids failed by mental health care. Australian Doctor. 27 April, p.42
Deuble L, Whitehall JF, Bolisetty S, Patole SK, Ostrea EM* and Whitehall JS. Environmental pollutants in meconium in Townsville, Australia.Department of Neonatology, Kirwan Hospital for Women, Townsville. Deparment of Pediatrics, Wayne State University, Michigan.
Isaacs, D and Sewell, J R. 2003. Children with chronic conditions. Medical Journal of Australia. 179:235-6; 1 September
Landrigan, P J et al. 1998. Children's health and the environment: A new agenda for prevention research. Environmental Health Perspectives 106, Supplement 3:787-794.
United States. Centers for Diseases Control. National Center for Environmental Health. CDCs monitoring program. Available at www.cdc.gov/nceh/tracking
World Health Organisation. 2003. Intergovernmental Forum on Chemical Safety. Forum-IV, Fourth Session. Protecting children from harmful chemical exposures. Decision Document.
End of Document
IPEN Body Burden Community Monitoring Handbook - 2005.
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