Objective To explore the effects of gestation exposure to dibutyltin dilaurate (DBTD) on the activity of enzymes in the testis and the spermatogenesis function in the mature male offspring of Wistar rats. Methods The pregnant rats were treated with DBTD by gavage at the doses of 0, 10, 20 and 30 mg/kg for days, from 12th-20th days of gestation. On 70th postnatal day, 10 male offspring rats were selected randomly from each group for measurements of the viscera coefficient of testis and the sperm count in epididymis, the activity of enzymes of testis was determined by spectrophotometry. Results There were no significant differences seen in the body weight gain of pregnant rats from days 12-20 of gestation, litter size, sex ratio of fetuses and body weight of male offspring rats between the experimental groups and the control group. The testis weight and viscera coefficient of testis in 30 mg/kg group increased significantly compared with the control group(P

Objective:To investigate epidemiological characteristics and influencing factors on dust-exposed working years of pneumoconiosis cases in Yantai.Methods:In January 2020, By Cluster sampling way, Using descriptive statistics to analyze dust-exposed working years of the reported 3307 new cases of pneumoconiosis from 2009 to 2019 in Yantai. Analyzing the variation trends by the chi-square trend test. Analyzing single fator by chi-square test. Using multiple classification Logistic Regression analysis to analyze multiple influencing factors.Results:The dust-exposed working age of pneumoconiosis cases decreased by years ( P<0.05) . The starting age of dust exposure of cases increased year by year, while positively correlated with the dust-exposed working age ( r=-0.217, P<0.05) . The years of dust exposure, starting age of dust exposure, industry, type of economy and scale of enterprise were main influence factors on the dust-exposed working age of pneumoconiosis cases. Conclusion:We should strengthen the management on prevention and control condition of pneumoconiosis in metal smelting and processing industry and privately-owned, small and micro enterprises, and pay attention to workers starting exposed to dust in the age of ≥28 years old.

Objective:To investigate epidemiological characteristics and influencing factors on dust-exposed working years of pneumoconiosis cases in Yantai.Methods:In January 2020, By Cluster sampling way, Using descriptive statistics to analyze dust-exposed working years of the reported 3307 new cases of pneumoconiosis from 2009 to 2019 in Yantai. Analyzing the variation trends by the chi-square trend test. Analyzing single fator by chi-square test. Using multiple classification Logistic Regression analysis to analyze multiple influencing factors.Results:The dust-exposed working age of pneumoconiosis cases decreased by years ( P<0.05) . The starting age of dust exposure of cases increased year by year, while positively correlated with the dust-exposed working age ( r=-0.217, P<0.05) . The years of dust exposure, starting age of dust exposure, industry, type of economy and scale of enterprise were main influence factors on the dust-exposed working age of pneumoconiosis cases. Conclusion:We should strengthen the management on prevention and control condition of pneumoconiosis in metal smelting and processing industry and privately-owned, small and micro enterprises, and pay attention to workers starting exposed to dust in the age of ≥28 years old.