This non-stick pan coating can actually cause a decline in male sperm quality...

Compiled by: Gong Zixin

Microplastics refer to plastic particles smaller than 5 mm and are ubiquitous environmental pollutants that are commonly found in global ecosystems such as water, air, and soil. Microplastics mainly come from the degradation and weathering of various plastic items, such as car tires, paints, etc., and can also be intentionally added to consumer products such as cosmetics and non-stick cookware coatings as part of their manufacturing process.

In addition, microplastics have been detected in various human tissues and biological samples, including liver, lung, placenta, kidney, spleen, blood, sputum and feces. It is reported that microplastics can penetrate into the human body through ingestion, inhalation or skin absorption. Current research shows that children and adults ingest a large amount of microplastic particles every day, which may have adverse effects on human health.

Previous studies have highlighted the harmful effects of microplastics on wildlife, showing that these pollutants can cause tissue damage, oxidative stress and reproductive harm. However, evidence on the effects of microplastics on human health, particularly male reproductive health, is limited.

Recently, the team of Academician Huang Hefeng from the Obstetrics and Gynecology Hospital of Fudan University and the Institute of Medical Genetics and Development of Zhejiang University, together with Professor Cao Jia from the Third Military Medical University and Associate Professor Duan Shuyin from Shandong First Medical University, completed a study. By testing eight types of microplastics in semen and urine samples of 113 men from three different regions in China, microplastics were detected in all samples.

It is worth noting that exposure to polytetrafluoroethylene (PTFE), a commonly used non-stick pan coating, and the number of microplastic exposure types are closely related to a significant decline in sperm quality, affecting the total sperm count, sperm concentration, and sperm motility, suggesting that microplastic pollution may pose a risk to reproductive health. The relevant paper was published in eBioMedicine, a subsidiary of The Lancet.

This is the largest study to date that aims to investigate the types and distribution of microplastics in semen and urine in different regions, with a particular focus on the effects of exposure to multiple types of microplastics on semen quality.

To explore the exposure to microplastics in different regions, the researchers recruited 113 male volunteers with an average age of 32.72 years and an average BMI of 25.49 from Zhengzhou, Jinan and Xiaogan to participate in a health survey.

Identifying types of microplastics The researchers collected semen and urine samples from volunteers and analyzed them using Raman microscopy to detect eight types of microplastics: polystyrene (PS), polypropylene (PP), polycarbonate (PC), polyethylene (PE), polyvinyl chloride (PVC), polytetrafluoroethylene (PTFE), polyethylene terephthalate (PET), and acrylonitrile butadiene styrene (ABS). Semen quality parameters were assessed, including total sperm count, concentration, motility, and morphology. Statistical analyses, including univariate and multivariate models, were used to assess the relationship between microplastic exposure and semen quality, adjusting for confounding factors such as age, body mass index, smoking, and alcohol consumption.

Distribution of clustered microplastic types by region, semen, and urine Surprisingly, the team detected microplastics in all samples, with 3 to 5 types being the most common, with PS, PP, and PE having the highest detection rates. The study uniquely determined that PTFE, a coating material widely used in non-stick pans, was significantly associated with reduced sperm quality, including a decrease in total sperm count, semen concentration, and sperm motility.

These findings suggest that different types of microplastics may have different toxic mechanisms and bioaccumulation effects. Therefore, when humans are exposed to multiple microplastics at the same time, a synergistic effect will occur, further exacerbating the damage to the reproductive system.

Microplastic exposure, classified by cluster analysis of main semen parameters, is associated with poor semen quality Various microplastics are introduced in large quantities in cookware and food contact materials, especially PTFE particles, which are the main component of non-stick coatings, which are continuously released during high temperature and stirring. Previous studies have highlighted that wear and surface damage caused by long-term use of old plastic cookware may aggravate the release of PTFE. Therefore, this may also be the reason why PTFE is widely detected in the human body.

Although PTFE itself is considered chemically inert and relatively safe under normal conditions of use, its degradation product, perfluorooctanoic acid (PFOA), has endocrine disrupting properties and interferes with the synthesis and secretion of testicular steroid hormones. PFOA is used to make PTFE and is released into the environment during the production and degradation of PTFE-containing products. Heating a PTFE pan for half an hour releases gaseous PFOA and degrades the coating, especially at 486 °C, where PTFE nanoparticles in the air form PFOA and persist in the air.

The researchers noted that the results highlight the potential reproductive health risks posed by microplastics, especially PTFE pollution. Future research is worth further clarifying the potential mechanisms of the adverse effects of microplastics on male fertility and transgenerational effects.