The Association of Cadmium Exposure from Active and Passive Smoking with Sperm Quality, DNA Fragmentation, and Chromatin Decondensation in Male Partners of Infertile Couples

Abstract

Smoking is a major lifestyle factor associated with impaired male reproductive health, affecting both active smokers and individuals exposed to secondhand smoke. It also represents a significant source of cadmium (Cd) exposure, a toxic metal associated with altered sperm quality. This study aimed to evaluate the association between active and passive smoking and semen parameters, sperm DNA fragmentation, and chromatin decondensation, as well as cadmium (Cd) and zinc (Zn) levels in seminal plasma. A total of 280 men from infertile couples were included and categorized into three groups: 104 non-smokers (control), 90 active smokers, and 86 passive smokers. Semen samples were analyzed according to the WHO 2021 guidelines. Cadmium and zinc concentrations in seminal plasma were determined using inductively coupled plasma atomic emission spectroscopy (ICP-AES), and sperm DNA fragmentation and chromatin decondensation were evaluated. The findings indicated that both active and passive smoking were associated with impaired semen parameters, increased sperm DNA fragmentation and chromatin decondensation, decreased zinc levels, and elevated cadmium concentrations in seminal plasma.