Infertility | How Pesticides Linked To Male Infertility?
Infertility issues are increasing widely and there are several reasons for it. One of the most common and very important factors has been found by a team of researchers from the Indian Institute of Science (IISc) in Bangalore. These researchers obtained conclusive evidence from animal studies. Sathees C. Raghavan, associate professor in the department of biochemistry, and Robin Sebastian, a research scholar, recorded some significant cell death in the testes, the organ that produces sperm in mice. They found these organs were exposed to endosulfan. Endosulfan is a controversial pesticide which is widely used by Indian Farmers. Endosulfan became a highly controversial pesticide due to its acute toxicity, potential for bio accumulation and role as an endocrine disruptor. This pesticide has been used in agriculture in all over the world in order to control insect pests including white flies, aphids, leaf hoppers, Colorado potato beetles and cabbage worms. This pesticide is linked with infertility in men where it has been extensively used. This research has been recently published in the journal “Cell Death Discovery”.
According to researchers a significant reduction in sperm count and sperm motility was found in mice which can cause infertility in men. This pesticide induced infertility which was found to be male specific. Approximately thirty three percent of mice which were male specific were treated with endosulfan. These treatments showed the clear signs of infertility. Prof. Sathees Raghavan from the Department of Biochemistry, IISc, Bangalore and the senior author of the paper says that the impact of this deadly pesticide on mice is very small because we used lower doses but people are exposed to very higher doses and for a long time. Researchers studied per group ten animals and the experiment was repeated three times. They used a dose equivalent of 3 mg/kg of body weight in the experiment. This does is equivalent to that seen in places where people live. Compared with 20-700 microgram/liter serum concentration of endosulfan in humans, the treated mice had a serum concentration of just 40-60 microgram/liter. Researchers say that they not only used the lower serum concentration but the exposure duration was also for a very short time. They treated mice with four dose of endosulfan per day on every alternative day for eight days. However, each mouse received the 16 doses of endosulfan during the time of treatment. After going to detailed study, researchers found that among all organs like liver, lungs and testes were maximally affected after the very first day of treatment and kidney, intestine and brain were not affected. Report shows that number of red blood cells and platelets were also went down. Treatment of endosulfan on mice affected in the testicles like many somniferous tubules where sperm produced were devoided the mother cells that become sperms. Mother cells take around 30 to 35 days to become sperms. After completion of 35 days, researchers found the lower number of sperm count were available in endosulfan treated mice than those mice who did not get treated.
Raghavan says that after immediate exposure of endosulfan pesticide, high level of molecules particularly known as Reactive Oxygen Species level may interact with and can spoil the genetic material DNA which may increases the level of error prone DNA and can cause genomic instability within sperms. Reactive Oxygen Species is found to be the culprits who cause the DNA damage and DNA repairing mechanism. The morphology of sperms was normal but there was the dramatic reduction of sperm count and motility after the endosulfan treatment. After 25 days of endosufan treatment, the motility of sperm was affected at the day of 35; the effects of pesticides on sperm motility were not significant. So, please keep noted that mice were exposed to endosulfan pesticides for limited time periods and that’s why affect of pesticide on motility of sperm was not significant after 35 day but people living in the area where these pesticides are being used continuously. People exposure to endosulfan pesticide on regular basis may experience the effect on motility continuing to be significant if effects on humans are the same as seen in mice. In order to get the fertility test on mice, researchers conducted the mating experiment. After mating experiment on mice, they found about one out of three males were infertile after the endosulfan treatment.
Researchers from the Indian Institute of Science (IISc) in Bangalore did the double check to find the effect of pesticide on lower sperm count and less motility in mice. They conducted mating between pesticide treated male mice to breed with female mice which was not pesticide treated. This mating experiment was done three times in 35 days of pesticide treatment. First session was performed from 5 to 10 days, second session from 20 to 25 days and third session from 30 to 35 days. Researchers found thirty percent of male mice did not give any progeny. In all three mating session, the percentage of infertile male increases than those who did not get pesticide treatment. They found in all three windows of mating, 20 to 25 days window showed the higher level of infertile males. So, we can expect that after 25 days of pesticide treatment, the sperm count dropped to its lowest point and it has the least motility.
It has been found that endosulfan was regularly used on cashew plantation for over decades in Kasargod district of Northern Kerala and they have reported several types of health issues which occur due to use of these pesticides. Now Kerala and Karnataka have banned using these pesticides. The World Health Organization (WHO) has classified this pesticide as class ll. This pesticide is listed under the Stockholm convention which means persistent organic pollutant according to given its environmental impact. These harmful chemicals such as endosulfan can easily gain access and embed deep inside the cells of vegetables, fruits, cereals and pulses that we consume every day. These toxic things ultimately enter our body, directly or indirectly. We cannot survive without food and these foods are containing number of pesticides. So, selection of food is the first step towards ensuring food safety.