Objective To study the toxicity of circuit board powder on main organs, especially on reproductive system of male mice by oral feeding.
Methods Male ICR mice were fed with either normal diet or the mixed diet containing circuit board powder. Body weight and food intake were recorded regularly. After 90 days of dietary treatment, the mice were sacrificed, and the organs (brain, heart, liver, spleen, lung, kidney, and testis) were weighed and histopathologically examined. Organ coefficients were calculated. Levels of polybrominated diphenyl ethers (PBDEs) in liver and brain were determined. Motility and kinetic parameters of sperm were measured. Expression of Connexin43 protein in testis was observed by immunofluorescence.
Results The acute oral lethal dose (LD50) of male mice after treatment of 24 h lixivium of circuit board powder was greater than 10 000 mg/kg. After a 90 d subchronic experiment, the organ coefficients of liver (4.63& #177;0.39), kidney (1.72& #177;0.29), brain (1.02& #177; 0.13), and lung (0.51& #177;0.04) in the test group were significantly increased when compared with those in the control group (3.99& #177;0.42, 1.38& #177;0.16, 0.85& #177;0.15, 0.46& #177;0.06, respectively). Pathological damage was found in the liver and kidney of the tested mice. The PBDEs levels in liver (175.54 ng/g wet weight) and brain (29.60 ng/g wet weight) of the test group were significantly increased when compared with those (liver, 2.16 ng/g wet weight; brain, 0.12 ng/g wet weight) of the control group, respectively. No obvious changes in the organ coefficient, pathological section, and expression of Connexin43 protein were observed in the testis of both the test and control groups. There were no significant differences in the motility and kinetic parameters of sperm between the test and control groups.
Conclusion Pathological changes are found in the liver and kidney of adult male mice after 90-day diet containing circuit board powder, while no reproductive toxic effect is observed.
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