Soong Yung-kuei, is director of OBGYN at Chang Geng hospital, and has done research on the relationship between the environment and infertility. He points out that one of the factors in the increase of the inability to conceive is lead or mercury in male sperm.
對環境與不孕關係素有研究的長庚醫院婦產科主任宋永魁也指出，男人睪丸中含有鉛與汞，是導致不孕率提高的諸多理由之一。