Objectives: To investigate whether glutathione S-transferases (GST) genetic polymorphisms (GSTT1 rs1049055, GSTM1 rs10712361, and GSTP1 rs1695) are associated with susceptibility to noise-induced hearing loss (NIHL). Methods: These polymorphisms were analyzed in 444 NIHL and 445 normal hearing workers. In addition, total plasma GST activity was measured in all subjects. Results: Individuals with the GSTM1 null genotype had a statistically significantly increased risk of NIHL (odds ratio [OR] = 1.64, 95% confidence interval [CI] = 1.26 to 2.13) compared with those carrying a wild-type GSTM1 genotype. This effect was more pronounced among the workers exposed to 86 to 91 dB(A) (OR = 3.35, 95% CI = 1.54 to 7.31). Glutathione S-transferase activity of the NIHL workers was also lower than that of normal hearing workers (14.5 ± 5.1 U/ml vs 15.9 ± 6.3 U/ml, P = 0.010). Conclusion: Our results suggest that GSTM1 polymorphism is associated with susceptibility to NIHL.

Studies about the association between lead exposure and the elevation of blood pressure and risk of hypertension are varied, while available data on blood lead levels (BLL) in workers with lead-exposure are scarce. This research aimed to evaluate associations between BLL and blood pressure in an occupational population-based study in Jiangsu province, China. We enrolled 21,688 workers in this study. Information on socioeconomic and occupational background was obtained with face-to-face interviews. BLL, systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured, and hypertension status was confirmed. We found that workers in mini-factories had the highest average BLL (20.3 μg/dL; 95% CI, 19.0–21.6 μg/dL) for overall participants. The employees in private factories had higher BLL (9.6 μg/dL; 95% CI, 9.5–9.8 μg/dL). However, BLL was much lower (4.0 μg/dL; 95%CI, 3.7–4.2 μg/dL) in state-owned factories. Participants working in the electrical machinery and equipment manufacturing industry had higher BLL (9.1 μg/dL; 95% CI, 9.0–9.3μg/dL). Compared to those workers with ≤ 4.6 μg/dL BLL, workers with > 17.5 μg/dL BLL presented 1.34 mmHg and 0.70 mmHg average difference in SBP and DBP, respectively. The adjusted OR for hypertension was 1.11 (95%CI, 1.08–1.15) compared to the workers with > 17.5 μg/dL BLL and to those with ≤ 4.6 μg/dL BLL. In summary, we found that BLL was positively associated with SBP and DBP and with the morbidity of hypertension in occupational populations with a high concentration of lead exposure. It is important to formulate new standards of blood lead levels to screen for elevated lead exposure. In addition, a series of new systems of risk assessment should be established to further reduce and prevent lead exposure.

Acute or long-term exposure to N,N-dimethylformamide (DMF) can induce abnormal liver function. It is well known that DMF is mainly metabolized in the liver and thereby produces reactive oxygen species (ROS). The base excision repair (BER) pathway is regarded as a very important pathway involved in repairing ROS-induced DNA damage. Several studies have explored the associations between GSTM1, GSTT1, CYP2E1 polymorphisms and DMF-induced abnormal liver function; however, little is known about how common hOGG1, XRCC1 and APE1 polymorphisms and DMF induce abnormal liver function. The purpose of this study was to investigate whether the polymorphisms in the hOGG1 (rs159153 and rs2072668), XRCC1 (rs25487, rs25489, and rs1799782), APE1 (rs1130409 and 1760944) genes in the human BER pathway were associated with the susceptibility to DMF-induced abnormal liver function in a Chinese population. These polymorphisms were genotyped in 123 workers with DMF-induced abnormal liver function and 123 workers with normal liver function. We found that workers with the APE1 rs1760944 TG/GG genotypes had a reduced risk of abnormal liver function, which was more pronounced in the subgroups that were exposed to DMF for G polymorphism may be associated with DMF-induced abnormal liver function in the Chinese Han population.

Background: Occupational noise exposure in the workplace is a significant health problem and hypertension is a widespread chronic disease. This study aimed to investigate whether occupational noise exposure is associated with hypertension in a Chinese population. Methods: A total of 286 hypertensive workers and 630 normotensive workers were enrolled and analyzed in a case-control study. Results: We revealed that workers exposed to noise can increase the risk of hypertension (adjusted OR 1.52, 95% CI: 1.11–2.08). This effect was more pronounced in ever smoking group (adjusted OR 2.54, 95% CI: 1.16–5.53). When noise exposure combined with never drinking status, it can reduce the risk of hypertension (adjusted OR 1.48, less than 1.52). Conclusions: Our results provide a clue that occupational noise exposure may increase the risk of hypertension in a Chinese population.

Background: This study is to assess the correlation between blood concentration ranges of eight elements of tin smelting workers from Guangxi Liuzhou and their job type, working years, age, and sex. Methods: We collected blood samples of 218 tin smelting workers from a Chinese tin smelting factory and determined the levels of elements by inductively coupled plasma mass spectrometry. Results: Within the blood concentrations of eight metal elements of the objects, the blood concentration of copper and zinc is affected by the job type of comprehensive work; that of arsenic and mercury is affected by refining; and that of chromium, cadmium, and lead is affected by primary smelting. Conclusions: We present the remarkable influence of four job types on the blood concentration of seven trace elements.