Durban - The United Nations has published a disturbing expert report which suggests that hundreds of hormone-disrupting chemicals may be implicated in the increasing rate of sexual deformities, infertility, cancers and other reproductive problems in people and wildlife across the world.
The new scientific report for the World Health Organisation and the UN Environment Programme suggests that a family of more than 800 widely used synthetic chemicals could be linked partly to the rapid increase in childhood asthma, type 2 diabetes, attention deficiency hyperactivity disorder, thyroid disease, autism and even obesity.
It cites recent studies which suggest that babies exposed to unusual levels of male or female hormones while still in the womb could undergo an alteration of their brain structure in some cases, to the extent of changing their sexual orientation permanently.
The main focus of the report is on synthetic chemicals known as endocrine-disrupting chemicals (EDCs) which interfere with the normal function of human and animal hormones, such as testosterone and oestrogen.
The scientists are worried about the fivefold increase in the rate of testicular cancer in northern Europe over the past 50 years, as well as the poor semen quality of men in richer nations, which has reduced their ability to father children.
Scientific studies suggest that 20-40 percent of young men in Denmark, Finland, Germany, Norway and Sweden have sub-fertile sperm counts.
However, very little data was available from African countries and other developing nations on the effects of endocrine-disrupting chemicals.
Increasing numbers of infant boys were now being born with cryptorchidism (undescended testicles) and hypospadia (a deformity of the penis opening).
Nearly 27 percent of adults in the US were obese, while the number of diabetics was increasing rapidly, especially in richer nations.
They noted that the female menstrual cycle and ovulation were also highly regulated by a variety of natural hormones, and if women were exposed to certain synthetic hormones, they could suffer from irregular periods, shorter or longer cycles, and more menstrual pain and bleeding.
“The speed with which the increases in disease incidence have occurred in recent decades rules out genetic factors as the sole plausible explanation,” said Professor Ake Bergman of the University of Stockholm, lead author of the latest report on endocrine-disrupting chemicals published last month.
“Environmental and other non-genetic factors – including nutrition, age of mother, viral diseases and chemical exposures – are also at play, but are difficult to identify,” said Bergman, who was one of 16 experts who spent almost two years reviewing the latest medical research on endocrine-disrupting chemicals.
In the animal world, there was now more evidence of skewed sex ratios and cases in which female fish became masculinised, while male fish became feminised after being exposed to chemical effluents from paper mills, sewage treatment works and other sources of chemical pollution.
In many cases, evidence of gender-bending properties in some chemicals was mirrored in humans and animals, suggesting medical authorities should pay more attention to the warning bells from nature.
Nevertheless, there was already evidence that some baby boys showed early signs of feminisation from exposure to a common plastic-softening chemical while still in the womb, while baby girls exposed to high levels of male hormones became more masculine when they reached puberty.
In the animal world, there were several examples of sexual alterations caused by exposure to endocrine-disrupting chemicals in the environment.
Among the animal studies featured in the UN report is a case study from South Africa which showed unusual testicle deformities in eland and feminised catfish exposed to synthetic chemicals in a nature reserve outside Pretoria.
Overall, the authors said they were concerned there had been a failure by health authorities to discover the underlying causes of recent trends in endocrine diseases and disorders. While there were still several uncertainties and knowledge gaps, the current decline in human and animal health was “too important to ignore”.
“Right now, only a narrow spectrum of chemicals and a few classes of EDCs are measured, making up the tip of the iceberg.’’ - The Mercury