Puberty comes early in boys exposed to common insecticide
Pesticides and insecticides are commonly used these days to control pests and insects in our gardens, farms and natural surroundings.
But environmental exposure to common pesticides has many effects and one of them is that it causes boys to reach sexual maturity earlier.
This was discovered in a study from the University of China.
The class of pesticides studied is called pyrethroids and it accounts for almost 30 per cent of insecticides used globally. These insecticides are known endocrine-disrupting chemicals which interfere with the body’s endocrine system and hormones produced.
Previous research has shown that early puberty increases the risk of several diseases in adulthood such as testicular cancer in men and breast cancer in women.
Pyrethroids are used both indoors and outdoors to kill mosquitoes and other insects and are also sprayed on crops. Human beings are likely to be exposed to the insecticide through food and residential use.
Evidence of exposure to pyrethroids is detected in human urine as a metabolite or molecule called 3-phenoxybenzoic acid (3-PBA).
Previous research has shown that early puberty increases the risk of several diseases in adulthood such as testicular cancer in men and breast cancer in women. Early puberty can also stunt growth and cause several behavioral problems.
Today a boy’s body matures between the age of 9 years and 14 years on an average. Scientists believe that many factors are responsible for the increasingly early onset of puberty in boys and girls, including environmental toxins.
The research team found in a study of 463 Chinese boys of ages 9 to 16 years, that a 10 per cent increase in 3-PBA was associated with a 4 per cent increase in level of luteinizing hormone (LH) and follicle-stimulating hormone (FSH). Both these hormones are responsible for the increased production of testosterone.
An increased level of 3-PBA increased the probability of a boy being at an advanced stage of genital development by 73 to 110 per cent.
As it is difficult to investigate and measure the cause of environmental risk factors in humans, the researchers tested mice to understand how pyrethroids affects the timing of puberty. After mice were exposed to a relevant level (as present in humans) of cypermethrin, a widely used pyrethroid insecticide, they observed an accelerated onset of puberty in mice.
Researchers concluded that given the increased use of pyrethroid insecticides, it is highly likely that these chemicals have an effect on children’s health which should be assessed further.
With these experiments the researchers demonstrated that cypermethrin had a direct effect by inducing testosterone formation and interfering with intracellular processes which are critical to male sexual development.
The use of pesticides and insecticides is increasingly having an effect on our health and wellbeing. Previous studies have shown that exposure to pesticides from food can cause lowered sperm count in men and pesticide exposures are increasingly being linked to neurodevelopmental disorders like the autism spectrum disorders. But its not only our health and wellbeing which is being affected. According to previous research use of pesticides is also diminishing biodiversity in streams and rivers which is essential for human survival.
These studies are important in directing our focus on the effect of pesticides and finding ways on how to diminish its use in the long run. Hopefully the scientific community will find a way soon.
Source: The Endocrine Society