Chemical toxics are man-made substances, mostly as a result of industrial processes, which can have a detrimental effect on living organisms.
It takes many years for these chemical toxicants to biodegrade and they are therefore persistent for decades in nature. It should be noted that these substances are lipophilic – they accumulate in fatty tissues, so their levels increase as we move up the trophic chain – and volatile, as they can evaporate and can travel long distances through air and water.
These substances are known as POPs or persistent organic pollutants.
A global problem
The distribution of chemical toxics is planetary, as it is possible to find them even in places and areas where they have never been used. Consequently, we are all exposed.
However, it should be mentioned that the main route of exposure to these toxicants is through food, especially in the case of dairy products, fish and meat.
There are different types of POPs, some of them more frequent in industrial and/or agricultural sectors, so that certain groups such as workers in the agricultural sector, scrap metal workers, miners or workers in the electrical sector, among others, may be at risk.
Relationship between chemical toxics and fertility
POPs can have immediate and/or chronic effects on health. Some are endocrine disruptors, i.e. they cause hormonal imbalances because they can mimic, substitute or even inhibit the action of hormones, a fact that causes uncontrolled biochemical reactions, especially in embryonic development.
Thus, the lack or excess of a particular hormone can cause major disturbances in reproductive development, changes in sexual behavior, birth defects and depression of the immune system. It can also lead to a decrease in sperm count, loss of fertility, increased breast, prostate and testicular cancer.
In turn, in both women and men, they can cause thyroid cancer, cardiovascular diseases, respiratory diseases such as asthma, endocrine diseases such as obesity or diabetes, and even neurological diseases such as autism, Parkinson’s or Alzheimer’s disease.
One of the main problems of these toxins is that they can be measured in different parts of the body, such as blood, urine or milk, although it is not possible to determine the percentage of responsibility of these toxins in cases of sterility. Basically, because multiple causes may be involved in sterility.
Exposure to POPs can start from the moment of conception, since, for example, PCBs (polychlorinated biphenyls) have been found in semen. As they accumulate in fatty tissues they can pass into the blood and cross the placenta during embryonic and fetal development, as well as be excreted in breast milk and transferred to newborns during lactation. For this reason, humans and other mammals are exposed to higher levels of these pollutants during the period of their lives when they are most vulnerable.
What can be done to avoid and prevent them?
To achieve this, the involvement of governments around the world is essential. In 2001, the Stockholm Convention was signed by 169 countries with the aim of protecting human health and the environment from POPs. The goals of the Convention are: to eliminate hazardous POPs (21 included in the Convention), to support the transition to safer solutions, to propose new POPs for action and to work together for a future free of pollutants.
The benefits and scope of the Stockholm Convention will depend on the fact that the public is aware of its contents and that the governments assume compliance.
In terms of prevention, and considering that it is quite possible that the damage may be irreversible and that the extent of the damage may be different, preventive measures may vary in each case. Sperm cryopreservation may be a good preventive measure in severe cases.