European scientists have recently confirmed the toxicity of a group of compounds known as PCBs found in plastics and dyes on sperm. However, these substances do not cause significant harm to reproductive capabilities.
PCBs, or polychlorinated biphenyls, are a group of harmful byproducts consisting of 200 different compounds that can cause genetic abnormalities in fish species. They are essentially a mixture of synthetic organic chemicals and are widely used in industrial applications, including the production of insulating materials, plasticizers in plastics, paints, rubber, and colorants. Humans absorb PCBs primarily through food. The U.S. Environmental Protection Agency reported that approximately 700,000 tons of PCBs were produced in the United States before a strict ban was implemented in 1977.
Dr. Marcello Spano and colleagues from the Italian National Agency for Environmental Protection, Energy, and Technology have investigated the impact of PCBs on sperm by examining changes in chromatin—a component made up of DNA and proteins related to chromosome formation. About 700 men from Sweden, Poland, Ukraine, and Greenland participated in the study. The researchers quantified the PCB marker, hexachlorobiphenyl, in the blood while also exploring the lifestyles, occupations, and reproductive histories of the volunteers.
The results indicated that the average DNA damage in sperm was 10%, and most of the participants had normal reproductive capabilities. Issues began to emerge when DNA damage reached 20%. “Exposure to PCBs negatively impacts sperm quality, especially in individuals with a pre-existing high rate of defects,” Spano noted.
It is noteworthy that the increase in damage corresponding to PCB exposure was only observed in European men, while nearly 200 Inuit individuals from Greenland did not exhibit similar issues. Spano suggested that the reason might be due to differences in genetic traits and lifestyles—factors that help mitigate the harmful effects of PCBs. In the near future, the research team will focus on studying the effects of PCBs on fetal development.
Mỹ Linh (according to Reuters, Times)
