XENO-ESTROGENS : A THREAT TO HUMAN AND ANIMAL LIFE
Xeno-estrogens are synthetic substances that differ from those produced by living
organism and imitate or enhance the effects of estrogens. The estrogenic stimulation is
an unintended side effect of these agents or their metabolites. The field of xeno-
hormones is new and has been existing since 1991 only. These chemicals directly
disrupt the endocrine system of the body and thereby affect the normal body functions.
The organs which are mostly at high risk are male and female reproductive systems,
although skeleton, thyroid, liver, kidney and immune system are also affected. Some of
these substances like DDE ( a metabolite of DDT ) may persist in the body fat for
decades. There are apprehensions pointing towards the cumulative biochemical
disruptions in genetic material that may even be transmitted through generations. Due
to their extensive use, these chemicals have been polluting the environment globally
during last 50 years. Pesticides were previously thought as the source of xeno-
estrogens. However many pharmaceuticals, chlorinated pesticides, polychlorinated
biphenyls and certain chemicals used in plastics and solvents have also been identified.
Infact about 100000 registered chemicals have hormone like activity besides having
toxic and carcinogenic effects.
MECHANISM OF ACTION : To exert any effect, hormones must first bind with specific
proteins called receptors to form hormone-receptor complex which bind’s to DNA in a
cell’s nucleus to activate specific genes. Xeno-estrogens either occupy the receptor
sites to prevent hormone binding or result in inappropriate activation of genes, causing
reduction and improvement in cellular activity. This way they interfere with normal
hormone functions of the body. They may cause permanent or irreversible damage to
the developing embryo and new born and their sexual, physical or mental development
may be arrested. In an experiment 10 commonly available organo-chlorines were mixed
at one tenth of their individually active dose, the potency (measured as cell proliferation)
noticed was 10 times higher than expected. These results indicate that they are more
potent together even at lower concentrations.
HOW PEOPLE ARE EXPOSED : Xeno-estrogens enter the human body through food
(meat of animals), contaminated food or water. In fatty tissues of animals In fatty tissues
of animals these substances accumulate for decades. Contaminated water and
vegetables containing pesticides are also responsible. Plastic bottles containing drinking
water have been found to contain bisphenol-A of which 2-5 parts per billion has been
found enough to cause the breast cancer cells to proliferate. Alkylphenol levels from
detergent breakdown products are high. Preservative methyl paraben used in skin
lotions and gels are also weak estrogen. Sub-cutaneous administration of butyl paraben
produces a positive estrogenic response on uterine tissues.
IMPORTANT MEASURES TO BE ADOPTED :
1. Don’t use plastic items to store food and water. Glass or ceramics are preferable.
2. Use simple detergents with fewer chemicals.
3. Minimize the use of chemical pesticides. Natural pest control measures like
integrated pest management must be adopted.
4. Use of hormone mimicking chemicals in consumer products should be stopped.
5. Avoid using organo-chlorines in products like PVC plastics, dry cleaners etc.
6. Don’t use herbicides; instead use a cup of salt in a gallon of vinegar.
7. Use of sun screen lotions, gels and other cosmetic items should be minimized .
Natural oils as skin moisturizers should replace these items.
8. Harmful food preservatives should be banned.
9. Waste effluents from factories should not be diverted to water bodies.
10. Extensive use of shampoos should be discouraged.
-DR. NAVRAJ SINGH SANDHU, www.navraj@gmail.com