The last research that famed toxicologist Lin Chieh-liang (林杰樑) participated in before his death last month shows that the level of lead accumulation in semen is inversely correlated with men’s sperm count.
Conducted by a research team at Chang Gung Memorial Hospital in Linkou and with Lin as one of the contributors, the study found that semen lead concentration was significantly higher among patients with lower sperm count, contributing to infertility among these men.
The result was published in Reproductive Biology and Endocrinology last year.
A total of 341 male partners of infertile couples attending the reproductive center of the hospital were recruited for the study, excluding patients with a history of heavy metal exposure or who resided in areas known to have heavy metal contamination, according to the article.
Demonstrating that the sperm count was negatively associated with semen lead concentration in men without occupational exposure to lead, the research team concluded that “chronic systemic low-level exposure to environmental toxicants such as lead may damage the reproductive function in general population.”
To their knowledge, the study is the first in the field to show that “low level of lead accumulation in seminal plasma may affect sperm amount for men without occupational exposure to lead,” it said.
Environmental lead exposure can result from long-term contact with poor-quality, colorful plastic products such as straws, toys and candy wrappers, as the coloring might be lead-based.
“When we use colorful drinking straws, we might be consuming lead, especially when the beverage is of higher temperature,” said Yen Tsung-hai (顏宗海), a toxicologist at the same hospital. “The lead might find its way into the human body through the skin, respiratory tract or mouth. And it could get into the semen too, leading to a reduced sperm count.”