OBJECTIVETo analyse the male reproductive toxicity of carbaryl.

METHODSThirty-one male carbaryl exposure workers and 46 male administrators in the office in a pesticide factory were selected as the exposure group and internal control group respectively, and 22 male administrators in a center for disease control and prevention were served as the external control group. In order to evaluate the exposure levels, the concentrations of carbaryl, methyl isocyanate, ammonia and phenol in the ambient air of the work place in these three groups were monitored simultaneously for three consecutive days. Moreover, three workers in the exposure group and the external control group were selected to evaluate the amount of carbaryl of individual and dermal contamination for three consecutive days. After the semen were collected according to the standard method, the workers'semen qualities were analysed with WHO method, the sperm morphology and the sperm motility were evaluated using micro-cell slide spectrum technology and computer assisted sperm analysis (CASA) respectively.

RESULTSIn the exposure group, the concentrations of carbaryl and phenol (52.41 mg/m(3) and 0.08 mg/m(3) respectively) were significantly higher than those in the internal and external control group (P < 0.01 or P < 0.05). Furthermore, in the carbaryl exposure area the geometric mean concentration of carbaryl with the individual sampling was 7.38 mg/m(3), and the geometric mean of dermal contamination detected in the carbaryl exposure area was 862.47 mg/m(2). Carbaryl was not found in the external control area (P < 0.01). The seminal volume [(2.39 +/- 1.44) ml] and the sperm motility [(1.77 +/- 0.61) grade] were significantly lower than those in the external control group (P < 0.05), and sperm motion parameters such as linearity (LIN, 39.89% +/- 6.00%), straightness (STR, 71.51% +/- 11.22%), straight line velocity [VSL, (26.29 +/- 7.84) microm/s] and beat cross frequency [BCF, (3.99 +/- 1.55) Hz] were lower than those in the internal and external control group (P < 0.05), while the abnormal rates of viscidity, sperm motility and total aberration rate were higher than those in the external control group (P < 0.05).

CONCLUSIONOccupational exposure to carbaryl production can affect the workers'sperm and semen quality to certain extent.