Drinking-water disinfection by-products and semen quality: a cross-sectional study in China.
BACKGROUND
Exposure to disinfection by-products (DBPs) has been demonstrated to impair male reproductive health in animals, but human evidence is limited and inconsistent.


OBJECTIVE
We examined the association between exposure to drinking-water DBPs and semen quality in a Chinese population.


METHODS
We recruited 2,009 men seeking semen analysis from the Reproductive Center of Tongji Hospital in Wuhan, China, between April 2011 and May 2012. Each man provided a semen sample and a urine sample. Semen samples were analyzed for sperm concentration, sperm motility, and sperm count. As a biomarker of exposure to drinking-water DBPs, trichloroacetic acid (TCAA) was measured in the urine samples.


RESULTS
The mean (median) urinary TCAA concentration was 9.58 (7.97) μg/L (interquartile range, 6.01-10.96 μg/L). Compared with men with urine TCAA in the lowest quartile, increased adjusted odds ratios (ORs) were estimated for below-reference sperm concentration in men with TCAA in the second and fourth quartiles (OR = 1.79; 95% CI: 1.19, 2.69 and OR = 1.51; 95% CI: 0.98, 2.31, respectively), for below-reference sperm motility in men with TCAA in the second and third quartiles (OR = 1.46; 95% CI: 1.12, 1.90 and OR = 1.30; 95% CI: 1.00, 1.70, respectively), and for below-reference sperm count in men with TCAA in the second quartile (OR 1.62; 95% CI: 1.04, 2.55). Nonmonotonic associations with TCAA quartiles were also estimated for semen parameters modeled as continuous outcomes, although significant negative associations were estimated for all quartiles above the reference level for sperm motility.


CONCLUSIONS
Our findings suggest that exposure to drinking-water DBPs may contribute to decreased semen quality in humans.
Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China.
Qiang
Q
Zeng
Yi-Xin
YX
Wang
Shao-Hua
SH
Xie
Liang
L
Xu
Yong-Zhe
YZ
Chen
Min
M
Li
Jing
J
Yue
Yu-Feng
YF
Li
Ai-Lin
AL
Liu
Wen-Qing
WQ
Lu
D000328:Adult; D015415:Biomarkers / Q000652:urine; D002681:China; D003430:Cross-Sectional Studies; D004202:Disinfectants / Q000633:toxicity*; D060766:Drinking Water / Q000032:analysis; D004781:Environmental Exposure; D004784:Environmental Monitoring; D006801:Humans; D008297:Male; D016017:Odds Ratio; D055101:Semen Analysis; D013076:Sperm Count; D013081:Sperm Motility / Q000187:drug effects; D013094:Spermatozoa / Q000187:drug effects* / Q000502:physiology; D014238:Trichloroacetic Acid / Q000652:urine*; D014874:Water Pollutants, Chemical / Q000633:toxicity* / Q000652:urine*; D055815:Young Adult
D015415:Biomarkers; D004202:Disinfectants; D060766:Drinking Water; D014874:Water Pollutants, Chemical; D014238:Trichloroacetic Acid