Call for urgent action on plastic additives linked to long-term fall in sperm counts

Action must be taken to curb the use of plastic additives linked to plummeting sperm counts, a leading reproductive scientist has warned as splits over chemical regulation contributed to the collapse of a crucial treaty on plastic pollution.

- Damien Gayle

Across the world, sperm counts have been declining at a rate of about 1% a year for the past 50 years, and human fertility more generally has been diminishing at a similar rate, studies have shown.

Increasing levels of obesity, sedentary lifestyles and ageing populations have all been held up as possible causes. But according to Dr Shanna Swan, professor of environmental medicine and public health at the Icahn School of Medicine at Mount Sinai in New York City, it is environmental factors that play the most significant role.

Swan said the decline was largely, but not entirely, due to toxins in the environment that have the ability to interfere with steroid hormones.

In 2017, Swan and her colleagues published a meta-analysis showing a decline in sperm counts of almost 60% among men in North America, Europe and Australia between 1973 and 2011, which received widespread attention.