A study from Lund University, Sweden, states that young men exposed to high concentrations of a phthalate compound called di-(2-ethylhexyl)phthalate or DEHP have lesser mobility in their sperms, which could potentially cause problems with fertility.

Phthalates are chemicals added to plastic and vinyl to make them soft and pliable. According to the National Institutes of Health (NIH), USA, phthalates are used in:

Building materials such as polyvinyl chloride (PVC), lubricants, solvents, etc.

Personal care products such as shampoos, perfumes, hairspray, soap, moisturizers, nail polish, etc.

One could potentially get exposed to phthalates through food, water, or air, according to the NIH. Children could get exposed to phthalates by chewing on soft plastic or vinyl toys.

It has been reported that phthalates are harmful for human health, since they are considered to interfere with the hormonal system. Such chemicals are collectively known as “endocrine disruptors.” Additionally, research in humans and rodents suggests that DEHP could induce cancer formation via a multitude of pathways, such as DNA damage, activation of nuclear receptors, increased cells’ growth, increased invasiveness of cancer cells, etc. In many animal studies, exposure to phthalates is reported to affect reproductive structures.

The current study analyzed the effect of DEHP in humans. For the study, 314 young men between the ages of 18-20 in the general Swedish population were engaged to assess their reproductive hormones and semen quality. The men provided blood, urine, and semen for analyses. The level of exposure to DEHP was assessed by measuring the level of mono-(2-ethyl-5-carboxypentyl) phthalate (MECPP), which is a metabolite of the compound. Sperm motility and immaturity (marked by high DNA stainability) were also measured for the study.

The following results were obtained after analyses:

There was exposure to DEHP, as evidenced by the presence of MECPP in the urine of the men.

Men with increased MECPP presence in the urine showed decreased sperm motility.

Sperm motility was 11 percentage points lower in men with the highest DEHP exposure, when compared to those with the lowest exposure.

Men in the highest DEHP exposure group had the lowest sperm maturation.

The study derives its relevance from engaging men in the general population instead of those with fertility problems who are assessed more often. Says lead author of the study, Dr. Jonathan Axelsson (Lund University News and Press Releases), “There are other studies that support our findings with regard to the link between DEHP metabolites and sperm motility, but also studies that have not found any connection. Moreover, the substances break down in the body within a few days, so there is no cause for immediate concern. However, we should be aware that there may be a problem and that it can be an important issue for further research.”

By Mangala Sarkar, PhD