Lead and Infertility

I read the recent publication on lead and infertility with a great interest.1 Awadalla,et al, concluded that “semen quality of men with primary infertility does not have any correlation with BLL [blood lead level] at the cutoff value of 20 μg/dL.” I have some concerns on this work. Firstly, this work assessed only one parameter—lead—hence, it cannot be conclusive since the subjects might have been exposed to many other things that can result in impairment of sperm quality. Secondly, looking at the blood lead level determination, the clarification on the quality control is required since the blood lead determination usually has the problem of interference.