Occupational Health Risk Assessment of Benzene, Toluene, and Xylene in Shanghai / 生物医学与环境科学（英文）

Objective@#This study was designed to conduct a retrospective and systematic occupational health risk assessment (OHRA) of enterprises that used benzene, toluene, and xylene (BTX) in Shanghai, China.@*Methods@#All data for the study were obtained from 1,705 occupational health examination and evaluation reports from 2013 to 2017, and a semiquantitative model following Chinese OHRA guidelines (GBZ/T 298-2017) was applied for the assessment.@*Results@#The selected enterprises using BTX were mainly involved in manufacturing of products. Using the exposure level method, health risk levels associated with exposure to BTX were classified as medium, negligible, or low. However, the risk levels associated with benzene and toluene were significantly different according to job types, with gluers and inkers exhibiting greater health risks. For the same job type, the health risk levels assessed using the comprehensive index method were higher than those using the exposure level method.@*Conclusion@#Our OHRA reveals that workers who are exposed to BTX still face excessive health risk. Additionally, the risk level varied depending on job categories and exposure to specific chemicals. Therefore, additional control measures recommended by OHRA guidelines are essential to reduce worker exposure levels.

Study on urine biomarkers in 1,3-butadiene exposed workers / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To discuss the urine biomarkers in 1,3-butadiene exposed workers, and to provide basement for establishing biological limit value.</p><p><b>METHODS</b>44 BD exposed workers as exposure group and 25 BD non-exposed people as control group including 12 workers in boiler workshop in the same factory and 13 people in one public institute, we collected their in-end-of shift urine, then detected urine BD-derived mercapturic metabolites [3,4-dihydroxybutyl mercapturic acid (DHBMA),1- and 2-monohydroxy-3-butenyl mercapturic acid (MHBMA)] concentrations using UPLC-MS/MS method. Meanwhile, we detected air BD concentration with GC-FID in the workplace, and compared their relationship.</p><p><b>RESULTS</b>lgDHBMA and lg (MHBMA + DHBMA) levels in exposed group (lgDHBMA: 2.51 ± 0.44) µg/L, lg [MHBMA + DHBMA: (2.68 ± 0.27) µg/L] were higher than which in control group (lgDHBMA: (2.20 ± 0.25) µg/L, lg(MHBMA + DHBMA: (2.49 ± 0.34) µg/L), and the differences were significant (P < 0.01). Urine DHBMA was obviously influenced by air BD concentrations (r = 0.539, P = 0.001). The equation of Multiple Regression Analysis was y = 2.417 + 0.520x (x represents air BD dose, and represents urinary DHBMA level). Adjusted R(2) of this model was 0.262. Urinary MHBMA was not affected by smoking, alcohol and years of works.</p><p><b>CONCLUSION</b>Urine metabolite DHBMA in BD-exposed workers might be major biological exposure indice.</p>

The assessment of reliability and validity of musculoskeletal questionnaire / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To evaluate the reliability and validity of musculoskeletal questionnaire.</p><p><b>METHODS</b>A self-administered modified musculoskeletal questionnaire was used to investigate 12 098 workers from eight occupations, i.e. coal mining, petroleum, metallurgical, mechanical manufacturing, chemical, garment and railroad transportation industries and education. The Cronbach's α coefficient, analysis of covariance and multiple logistic regression were used to assess the reliability and validity of musculoskeletal questionnaire.</p><p><b>RESULTS</b>The consistent test between total items of Musculoskeletal Questionnaire and each factor showed that the range of Cronbach's α was 0.52 ∼ 0.92, except from vibration factor, other Cronbach's α was more than 0.7. All 55 items of Musculoskeletal Questionnaire were subjected to factor analysis, and ten latent factors were identified, which explained 55.17% of the total variance. The potentially hazardous working conditions could be categorized into seven dimensions (force, dynamic load, static load, repetitive load, climate factors, vibration exposure and environmental ergonomic factor), which consisted with the theory model. The results of covariance analysis indicated that there were significant difference among 7 dimension indices in different jobs (P < 0.01).</p><p><b>CONCLUSION</b>The modified Musculoskeletal Questionnaire is a valid and reliable tool for measuring musculoskeletal workload.</p>

Polymorphism of XRCC1 and chromosome damage in workers occupationally exposed to benzene / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To explore the relationship between the polymorphisms of DNA repair gene (XRCC1 194, 280 and 399) and the chromosomal damage induced by benzene.</p><p><b>METHODS</b>The chromosomal damage of the peripheral lymphocytes in 459 workers occupationally exposed to benzene and 88 non-exposed controls were detected with cytokinesis-block micronucleus (CBMN) assay. PCR-RFLP technique was used to measure polymorphisms in XRCC1 194, 280 and 399.</p><p><b>RESULTS</b>It was found that the MN frequency (2.12‰ ± 1.88‰) of the exposed group was significantly higher than that (1.19‰ ± 1.68‰) of the control group (P < 0.05), in the exposed group, the MN frequency (3.00‰ ± 2.76‰) of older workers (> 35 years) was significantly higher than that (2.02‰ ± 1.71‰) of younger workers (≤ 35 years) (P < 0.05). The effect of genetic polymorphisms of XRCC1 on CBMN was not found. The haplotypes AAA/BAA, AAB/AAB, ABA/ABA, ABB/ABB could associated with the increased frequencies of total micronucleus (P < 0.05).</p><p><b>CONCLUSION</b>Benzene exposure could result in chromosome damage. Age of workers and diplotypes of XRCC1 could associated with chromosomal damage induced by benzene.</p>

Association analysis of polymorphisms of metabolizing enzyme genes with chronic benzene poisoning based on logistic regression and multifactor dimensionality reduction / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To explore the association of polymorphisms of metabolizing enzyme genes with chronic benzene poisoning (CBP) comprehensively by case-control design.</p><p><b>METHODS</b>152 CBP patients and 152 workers occupationally exposed to benzene without poisoning manifestations were investigated. 30 single nucleotide polymorphisms (SNPs) in 13 genes such as CYP2E1 were tested by PCR-RFLP, sequencing approaches. Logistic regression model was used to detect main effects and 2-order interaction effects of gene and/or environment. Multifactor dimensionality reduction (MDR) was used to detect high-order gene-gene or gene-environment interactions.</p><p><b>RESULTS</b>Based on logistic regression, the main effects of GSTP1 rs947894, EPHX1 rs1051740, CYP1A1 rs4646903, CYP2D6 rs1065852 and rs1135840 were found to be significant (P < 0.05) while the confounding factors of sex, cigarette smoking, alcohol consumption and the intensity of benzene exposure were controlled. EPHX1 rs1051740 might be associated with CBP (P = 0.06). There existed 3 types of interactions were as followed: interactions of GSTP1 rs947894 with alcohol consumption, CYP2E1 rs3813867 with EPHX1 rs3738047, EPHX1 rs3738047 with alcohol consumption(P < 0.05), while the main effects of CYP2E1 rs3813867 and EPHX1 rs3738047 were not significant (P > 0.05). The other SNPs did not show any significant associations with CBP. According to MDR, a 3-order interaction with the strongest combined effect was found, i.e. the 3-factor combination of CYP1A1 rs4646903, CYP2D6 rs1065852 and CYP2D6 rs1135840.</p><p><b>CONCLUSION</b>Gene-gene, gene-environment interactions are important mechanism to genetic susceptibility of CBP.</p>

Susceptibility of chromosomal damage among workers exposed to vinyl chloride monomer / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To explore the association between chromosomal damage induced by vinyl chloride monomer (VCM) and polymorphisms of xenobiotic metabolism genes and DNA repair genes.</p><p><b>METHODS</b>Cytokinesis-block micronucleus (CBMN) test was performed to detect chromosomal damage in peripheral lymphocytes of 402 VCM-exposed workers. Multiplex PCR was used to simultaneously amplify GSTM1 and GSTT1 genes, other genetic polymorphisms were performed using a PCR-RFLP technique.</p><p><b>RESULTS</b>Multiple (adjusted) Poisson regression analysis showed that mean MN frequencies were significantly elevated for the intermediate (4000-40000 mg) and high (> 40000 mg) exposure groups as compared with the low exposure group (P = 0.003 and 0.03, respectively). For genetic polymorphisms, the exposed workers with CYP2E1 or XRCC1 Arg280His variance showed a higher CBMN frequency than their wild-type homozygous counterparts (P = 0.02); so did the workers with GSTP1 105Val/Val genotype or ALDH2 504Glu/Glu genotype than those with a combination of other genotypes (P = 0.01 and 0.003, respectively).</p><p><b>CONCLUSION</b>Our findings reveal that cumulative exposure dose of VCM and common genetic variants in genes, such as GSTP1, CYP2E1, ALDH2, XRCC1 Arg280His genotypes, are the major factors that modulate MN induction in VCM- exposed workers. Further study to investigate the relationship between individual characteristics and genetic susceptibility to VCM-caused chromosome damage is warranted, it is helpful for us to understand the mechanism of VCM metabolism, to find the biomarkers of susceptibility and to recognize the susceptible individuals in the primary prevention of VCM-caused damage.</p>

Genetic susceptibility of DNA damage induced by vinyl chloride monomer exposure / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To explore the association between DNA damage induced by vinyl chloride monomer (VCM) and polymorphisms of DNA repair genes and xenobiotic metabolism genes of VCM.</p><p><b>METHODS</b>Comet assay was employed to detect DNA damage. Based on the status of DNA damage, the VCM exposure workers were divided into two groups: DNA damage group (75) and control group (75). Case-control design was used to investigate the association between the genetic polymorphisms and DNA damage induced by VCM. Genotypes of XRCC1 (Arg194Trp, Arg280His and Arg399Gln), XPD (Ile199Met, Asp312Asn and Lys751Gln) and CYP2E1 were identified by the PCR-RFLP. PCR assay was used to detect positive and null genotype of GSTT1 and GSTM1.</p><p><b>RESULTS</b>Univariate analysis showed that the CYP2E1 c1c2/c2c2 and XPD751 Lys/Gln and Gln/Gln genotypes were significantly associated with the increased levels of DNA damage, XRCCI 339 Arg/Gln and Gln/Gln genotypes were significantly associated with the decreased levels of DNA damage (P < 0.01, P < 0.05, respectively). Logistic regression analysis showed that there was significant association between the genotypes of XRCC1 194, XRCC1 399, XPD 751, CYP2E1 and DNA damages. A prominent risk decreasing of DNA damage was observed for those individuals possessing XRCC1 399Arg/Gln + Gln/Gln genotypes (OR: 0.35, 95%CI: 0.12 approximately 1.01, respectively); The results also showed that there were significant associations between CYP2E1 c1c2/c2c2 and DNA damage both in high and low VCM-exposed groups (OR: 2.57, 95%CI: 1.01 approximately 6.59 and OR: 2.57, 95%CI: 0.99 approximately 6.87).</p><p><b>CONCLUSION</b>Cumulative exposure dose and genotypes of XRCC1 194, XRCC1 399, XPD 751 and CYP2E1 may modulate the DNA damage induced by VCM exposure.</p>

Synergistic interaction between MMP-3, VDR gene polymorphisms and occupational risk factors on lumbar disc degeneration / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To explore the synergistic interaction between MMP-3,VDR gene polymorphisms and occupational risk factors on lumbar disc degeneration.</p><p><b>METHODS</b>A case-control study including 178 cases of lumbar disc degeneration and 284 controls was carried out through questionnaire and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technology. Additive model was used to analyze the synergistic interaction between gene polymorphisms and occupational risk factors.</p><p><b>RESULTS</b>The non-conditional logistic regression analysis showed that bending/twisting, whole-body vibration, heavy physical workload, alleles 5A of MMP-3 (6A5A/5A5A) and A of VDR-Apa (AA/Aa) were significantly associated with lumbar disc degeneration(OR = 4.06, 8.96, 5.46, 1.96 and 1.70, respectively, P < 0.05). There were synergistic interactions between the mutation genotype 5A of MMP-3 and whole-body vibration exposure, between the mutation genotype 5A of MMP-3 and bending/twisting, and between the mutation genotype A of VDR-Apa and whole-body vibration exposure (SI: 13.27, 2.91 and 2.35 respectively, P < 0.05).</p><p><b>CONCLUSION</b>People with the mutation genotypes 5A of MMP-3 and/or A of VDR-Apa may have the increased risk of developing lumbar disc degeneration if they are exposed to whole-body vibration and/or bending/twisting.</p>

In vitro evaluation of cutaneous allergic reaction induced by chemicals using dendritic cells / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the use of dendritic cells derived from mice bone marrow to evaluate the cutaneous allergic reaction induced by chemical sensitizers.</p><p><b>METHODS</b>Dendritic cells derived from mice bone marrow were cultured and administrated with 2, 4-dinitrochlorobenzene (DNCB), nickel sulfate (NiSO4), sodium dodecyl sulfate (SDS) and hexyl cinnamic aldehyde (HCA), respectively. Cell membrane molecule CD86 and extracellular IL-1 beta, IL-6 and IL-12 were detected after 0, 1, 6, 12, 24, 36, 48 hour's administration, respectively.</p><p><b>RESULTS</b>CD86 expression reached the highest level after exposure to DNCB for 48 h, and increased by about 279% compared with the control (P < 0.05), while it was lower than that of control after administrated with NiSO4 and HCA for 1 h and 6 h, and SDS for 36 h, respectively (P < 0.05). Extracellular IL-1 beta increased greatly after exposure to NiSO4 just for 1 h, with the maximum at 48 h (298 pg/ml, P < 0.05), and after exposure to HCA for 6 h, with maximum at 48 h (84 pg/ml, P < 0.05). However, it didn't fluctuate significantly after administrated with DNCB and SDS respectively, compared with the control. Extracellular IL-6 increased significantly after exposure to NiSO4 for 1 h, with the maximum at 24 h (2152 pg/ml, P < 0.05). After exposure to HCA, extracellular IL-6 reached the maximum at 1 h (1403 pg/ml), and then it was decreased quickly, but still higher than the control (P < 0.05), while it didn't change significantly after treatment with DNCB and SDS, compared with the control (P > 0.05). Extracellular IL-12 was not detected out among all the groups.</p><p><b>CONCLUSION</b>Chemical sensitizer DNCB could induce the high expression of CD86 on DC membrane, and NiSO4 and HCA could induce DC to release IL-1 beta and IL-6. However, the irritant SDS had no such effect.</p>

Polymorphisms of FAS and FASL genes and susceptibility of silicosis / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To explore the relationship between polymorphisms of FAS and FASL genes and genetic susceptibility of silicosis.</p><p><b>METHODS</b>A case-control study was conducted. The case group was 183 male patients with silicosis and the control group was 111 male silica-exposed but without silicosis miners. Data on total dust concentrations was collected to estimate cumulative total dust exposure (CTE) of each subject and each person's characteristics and work history were obtained from questionnaire. Polymerase chain reaction re-strained fragment length polymorphism technique (PCR-RFLP) was applied to detect the single nucleotide polymorphisms (SNPs) of FAS-1377, FAS-670 and FASL-844. Associations between polymorphisms and risk of silicosis and stages, interactions between polymorphisms, between polymorphisms and CTE and smoking and haplotypes were analyzed.</p><p><b>RESULTS</b>There were no differences in the FAS-1377, FAS-670 and FASL-844 genotypes between the case group and the control group (P > 0.05). No association was observed between FAS-1377, FAS-670 and FASL-844 polymorphisms and silicosis and stages (P > 0.05). The frequencies of FAS-1377G/-670G haplotype in the cases (9.6%) were higher than those in the controls (3.6%) (P < 0.05). No interactions between the polymorphisms of different genes, the gene polymorphism and the total accumulative total dust, the gene polymorphism and smoking were observed (P > 0.05).</p><p><b>CONCLUSION</b>FAS-1377, FAS-670 and FASL-844 polymorphisms are not susceptible factors of silicosis. The FAS-1377G/-670G haplotype might be a susceptibility marker of silicosis.</p>

Low back pain prevalence of female workers in flat-grained veneer wood industry / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the low back pain(LBP) and its cause on female workers in flat-grained veneer wood industry.</p><p><b>METHODS</b>Bending posture was analyzed by observation and the prevalence of low back pain was investigated by physical examination and questionnaire among 299 female workers.</p><p><b>RESULTS</b>The prevalence of fatigue compliant in selecting, remending and sticking workers was 68.8%, 66.7% and 59.0%, respectively, which mainly involved in the part of low back. The prevalence of low back pain in selection (53.8%) and remending (58.7%) workers was higher than that in sticking workers (30.1%), which was in accordance with the tenderness between L4/L5 or L5/L6 and on the psoas major. Posture analysis indicated that the biggest bending range of selecting and remending workers (80 degrees ) was larger than that of sticking workers (60 degrees ), as well as the daily bending times[(4396+/-817), (1696+/-286), (1094+/-476)] and the time they kept bending[(6.5+/-0.6), (6.2+/-1.3), 4.5+/-0.9) h].</p><p><b>CONCLUSION</b>Bending posture is common among female workers especially those who work in selecting and remending and might be the major causes for the high prevalence of LBP in flat-grained veneer wood industry.</p>

Genetic polymorphism in cell cycle control genes and susceptibility of chromosomal damage in vinyl chloride monomer exposed workers / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To explore the relationship between genetic polymorphism of P53, P21, CCND1 and susceptibility of chromosomal damage induced by vinyl chloride monomer (VCM).</p><p><b>METHODS</b>183 workers occupationally exposed to VCM were involved in our study. Cytokinesis-block micronucleus (CB-MN) assay was used to detect chromosome damage in peripheral lymphocyte. PCR-RFLP technique was applied to detect polymorphisms in P53 gene (exon4, intron3 and intron6), P21 gene (exon2 and exon3) and CCND1 (exon4).</p><p><b>RESULTS</b>The risk of chromosomal damage for VCM-exposed workers with more than 30 yr was 1.2202 (95% CI: 1.0580 approximately 1.4072, P = 0.0062) compared with the younger workers, and the risk of female workers was 1.1491 (95% CI: 0.9841 approximately 1.3416, P = 0.0772) compared with male workers. The MN frequency in subjects with P53 intron6 mutant homozygous and heterozygous was higher than their wild-type homozygous counterparts (OR = 1.3032, 95% CI: 1.1285 approximately 1.6405, P = 0.0285). P53 exon4, intron3 and intron6 haplotype pairs of BBB/AAA and BAB/AAA were associated with the increased frequencies of micronucleus.</p><p><b>CONCLUSION</b>Among VCM-exposed workers, more than 30ys, female, carrying P53 intron6 mutated allele and BBB/AAA and BAB/AAA haplotype pairs have higher risk of chromosomal damage.</p>

Relationship between genetic polymorphism in hMTH1c.83, hOGG1c.326 and hMYHc.335 and risks of chronic benzene poisoning / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To explore the relationship between genetic polymorphisms in hMTH1, hOGG1 and hMYH and risks of chronic benzene poisoning (CBP).</p><p><b>METHODS</b>A case control study was conducted. One hundred and fifty-two BP patients and 152 workers occupationally exposed to benzene without poisoning manifestations were investigated. The polymerase chain reaction restrained fragment length polymorphism technique (PCR-RFLP) was applied to detect the single nucleotide polymorphisms (SNPs) on c.83 of hMTH1 gene, c.326 of hOGG1 gene and c.335 of hMYH gene.</p><p><b>RESULTS</b>There were 2.51 times (OR(adj) = 2.51, 95% CI: 1.14-5.49, P = 0.02) and 2.49 times (OR(adj) = 2.49, 95% CI: 1.52-4.07, P < 0.01) risks of BP for individuals carrying genotypes of hMTH1c.83Val/Met + Met/Met or hOGG1c.326Cys/Cys compared with individuals carrying genotypes of hMTH1c.83Val/Val or hOGG1c.326Ser/Cys + Ser/Ser, respectively. Compared with individuals carrying genotypes of hOGG1c.326Cys/Cy and hMYHc.335 is/His at the same time, there was 0.33 times (OR(adj) = 0.33, 95% CI = 0.15-0.72, P = 0.01) risks of BP for these with genotypes of hOGG1c.326Ser/Cys + Ser/Ser and hMYHc.335His/Gln + Gln/Gln simultaneously. In the smoking group, there was 0.15 times (OR(adj) = 0.15, 95% CI: 0.03-0.68, P = 0.01) risks of BP for subjects carrying genotypes of hMYHc.335His/Gln + Gln/Gln compared with these carrying genotypes of hMYHc.335His/His.</p><p><b>CONCLUSION</b>Polymorphisms of hMTH1 Val83 Met and hOGG1 Ser326Cys may contribute to altered risks of CBP, and potential interaction may exist among polymorphisms of hOGG1 Ser326Cys and hMYH His335Gln.</p>

Genetic polymorphism of CYP-1A1, CYP2D6 and risks of chronic benzene poisoning / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To explore the relationship between genetic polymorphisms of CYP-1A1 and CYP2D6 and risks of chronic benzene poisoning (BP).</p><p><b>METHODS</b>A case control study was conducted. 152 BP patients and 152 workers occupationally exposed to benzene without poisoning manifestations were involved. Polymerase chain reaction followed by restriction fragment length polymorphism (PCR-RFLP) technology was used for detecting the single nucleotide polymorphisms (SNPs) of MspI in the non-coding region of CYP-1A1 gene and c.188, g.212 position in the first extron of CYP2D6 gene.</p><p><b>RESULTS</b>The individuals with CYP1A1 MspI T/T genotype had a 1.32 times (95% CI: 1.05 approximately 1.65, P = 0.02) increased risk of BP compared with those carrying T/C and C/C genotypes. In no-smoking population, there was a 1.56 times (95% CI: 1.15 approximately 2.12, P = 0.003) increased risk of BP for subjects carrying CYP1A1 MspIT/T genotype compared with those carrying T/C and C/C genotypes. The individuals carrying CYP2D6 c.188 C/C or C/T genotype had a 1.23 times (95% CI: 1.05 approximately 1.42, P = 0.01) increased risk compared with those carrying T/T genotypes. In no-smoking population, there was a 1.23 times (95% CI: 1.04 approximately 1.47, P = 0.01) increased risk of BP for subjects carrying CYP2D6 c.188 C/C or C/T genotypes compared with those carrying T/T genotype. The single nucleotide polymorphism of g.212 position in the first extron of CYP2D6 gene had not been validated.</p><p><b>CONCLUSION</b>The individuals with CYP2D6 c.188 C/C, CYP2D6 c.188 C/T and CYP1A1 MspIT/T genotypes tend to be more susceptible to benzene toxicity.</p>

Relationship of genetic polymorphism in APE1 and ADPRT to risks of chronic benzene poisoning / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To explore the relationship between genetic polymorphisms in apurinic/apyrimidinic endonuclease (APE1) and ADP ribosyltransferase (ADPRT) and individuals' susceptibility to chronic benzene poison ing (BP).</p><p><b>METHODS</b>A case-control study was conducted. One hundred and fifty-two B P patients and 152 workers occupationally exposed to benzene without poisoning manifestations were investigated. The mismatched bases combined to create restriction site with restrained fragment length polymorphism technique (CRS-RFLP) was used for detecting the single nucleotide polymorphisms (SNPs) at Asp148Glu of APE1 gene and Val762Ala of ADPRT gene.</p><p><b>RESULTS</b>There was no significant difference in the distribution of genotypes of APE1Asp148Glu and ADPRTVal762Ala between the patients and the control groups. Compared with individuals having genotype of APE1Asp148Glu T/T without habit of alcohol consumption, there was a 4.13 times increased risk of BP for the alcohol user with genotype of APE1Asp148Glu T/T (OR = 4.13, 95% CI: 1.07 - 15.85, P = 0.03). The analysis of Logistic regression showed that smoking may play some role in modifying the risk of cironic benzene poisoning (OR = 0.33, 95% CI: 0.14 - 0.75, P = 0.01).</p><p><b>CONCLUSION</b>The genetic polymorphisms in APE1Asp148Glu, ADPRTVal762Ala are not related to the risk of BP. Potential interaction is found between alcohol consumption and polymorphism of APE1Asp148Glu. Further study is needed to elucidate this interaction.</p>

Relationship between single nucleotide polymorphisms of NRAMP1 gene and susceptibility to pulmonary tuberculosis in workers exposed to silica dusts / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To explore the relationship between polymorphisms of natural resistance-associated macrophage protein 1 (NRAMP1) gene and genetic susceptibility of pulmonary tuberculosis (PTB) in workers exposed to silica dusts.</p><p><b>METHODS</b>A 1:2 case control study of 61 male workers with PTB (50 silicosis patients and 11 unsilicosis workers) as the case group and 122 male PTB-free workers (100 silicosis patients and 22 unsilicosis workers) as the control group was conducted with the frequency matched for age of +/- 5 years, the job, the silica exposure, and the condition of cigarette smoking and alcohol drinking. The polymerase chain reaction-restrained fragment length polymorphism technique (PCR-RFLP) was used to detect the single nucleotide polymorphisms (SNPs) of NRAMP1 INT4 and D543N.</p><p><b>RESULTS</b>There was a 2.73 times (95% CI: 1.32 approximately 5.64) increased risk of silicosis for individuals with C allele of NRAMP1 INT4 compared with individuals carrying homozygote (G/G), while SNPs of NRAMP1 D543N was not associated with PTB (P > 0.05).</p><p><b>CONCLUSION</b>The G > C mutation of intron 4 of NRAMP1 gene might be a susceptible factor of silica for the workers exposed to PTB.</p>

Investigation on the association of safety perception and safety behaviors with occupational injuries in steel-workers / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To explore the association of occupational injuries, with their individual safety perception and safety behaviors in steel workers, so as to provide basis for preventing and controlling occupational injuries.</p><p><b>METHODS</b>Case-control design was used to compare the difference in safety perception and safety behaviors between the injury group and the control, and also to compare the difference in safety behaviors between different safety perception groups.</p><p><b>RESULTS</b>There were remarkable differences in attitude toward the safety degree of the work (chi(2) = 5.444, P < 0.05), and accidents happening (chi(2) = 4.552, P < 0.05) between case group and control group. There were remarkable difference in safety behaviors including manual operations instead of facilities (chi(2) = 10.015, P < 0.01), cleaning up, examining or adjusting machine during work (chi(2) = 7.351, P < 0.05), attention diversion (chi(2) = 10.937, P < 0.01) and unsafe wearing (chi(2) = 7.521, P < 0.05) between case group and control group. There were also significant differences in many safety behaviors between those who thought the job was safe or unsafe.</p><p><b>CONCLUSION</b>There is some association of occupational injuries with safety perception and safety behaviors. To reduce the occurrence of occupational injury, measures should been focused on strengthening safety management and controlling unsafe behaviors.</p>

Relationship of occupational injuries with social and economic factors / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To explore the relationship of occupational injuries with social and economic factors in chemical industry during 2000.01 - 2001.12.</p><p><b>METHOD</b>1:2 paired case-control study, univariable logistic regression analysis, principal component analysis, and multiple logistic regression analysis were used in this study.</p><p><b>RESULTS</b>Univariable analysis showed that occupational injuries had significant relationship with age, sex, education, employment pattern, technology, workplace, work changing, wage, family income, enterprise scale, enterprise proprietorship, projective device, operation rules, and training rules of work safety. The extracted four principal components (PC(1), PC(2), PC(3) and PC(4), ranked by contribution) gave good expressions to the initial 11 variables. The cumulative proportion of the four principal components reached 77.36%. PC(1) was the indicative factor of occupational injuries, which represented 46.69% information of initial variables. PC(2) was the kinetic factor of occupational injuries. PC(3) was the stable factor of occupational injuries. PC(4) was the sex factor of occupational injuries. The results of multiple conditional logistic regression analysis showed that occupational injuries had statistically significant relationship with PC(1) and PC(2). Among the initial variables, sex, employment pattern, income, scale of enterprise, and property of enterprise were more prominent.</p><p><b>CONCLUSION</b>Occupational injuries are related with multiple social and economic factors, which often interact on each other. The prevention and control of occupational injuries should require a comprehensive approach, including training and education of work safety, improving workers' consciousness of self-protection, and enhancing proprietors' consciousness of work safety.</p>

Case-only study on the relationship between genetic polymorphisms in toxicant metabolizing enzymes and risk of occupational chronic benzene poisoning / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To explore the effects of interaction between environmental exposure factors and genetic polymorphism in toxicant metabolizing enzymes on risk of occupational chronic benzene poisoning.</p><p><b>METHODS</b>One hundred and fifty-two cases of chronic benzene poisoning were analyzed for the risk by case-only study.</p><p><b>RESULTS</b>The frequency of non-null GSTT1 gene in benzene poisoning workers with moderate benzene exposure level was higher than that in cases with lower benzene exposure (68.63% vs 38.00%, OR(adj) = 4.32, 95% CI 1.75 - 10.66, P = 0.002). The frequency of NQO1 C.609T/T gene in alcohol drinking group was higher than that in non-drinking group (61.11% vs 20.00%, OR(adj) = 8.03, 95% CI 2.28 - 28.25, P = 0.001), moreover, it was higher in workers with smoking and drinking than that in the rest group, and in drinking x exposure level workers than that in non-drinking x exposure level workers (85.71% vs 22.76%, OR(adj) = 18.62, 95% CI 2.01 - 172.72, P = 0.01 and 61.11% vs 20.00%, OR(adj) = 3.18, 95% CI 1.55 - 6.52, P = 0.002 respectively). The frequency of non-null GSTM1 gene was also higher in drinking x exposure level workers than that in non-drinking x exposure level workers (66.67% vs 47.06%, OR(adj) = 1.99, 95% CI 1.05 - 3.76, P = 0.036).</p><p><b>CONCLUSION</b>There is interaction between the polymorphism of GSTT1 gene and moderate benzene exposure level; non-null GSTM1 gene and drinking x exposure level increase the risk of occupational chronic benzene poisoning; polymorphism of NQO1 gene C.609 also interacts with drinking, while polymorphism of NQO1 gene and drinking x smoking may further increase the risk of occupational chronic benzene poisoning.</p>

DNA damages of liver cells and expressions of DNA damage repair genes in rats exposed to vinyl chloride monomer / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study DNA damages of liver cells in rats exposed to vinyl chloride monomer (VCM), and the expressions of DNA damage repair enzymes including O(6)-methyl guanine-DNA methyl transferase (MGMT), X-ray repair cross-complementing group 1 (XRCC1) and X-ray repair cross-complementing group 3 (XRCC3); and to explore the repair mechanism of DNA damage induced by VCM.</p><p><b>METHODS</b>Rats were exposed to VCM by intraperitoneal injection. DNA damages were detected by single cell gel electrophoresis (comet assay). The expressions of DNA damage repair enzymes were measured by immunohistochemical methods.</p><p><b>RESULTS</b>The percentages of comet cells in low, moderate, and high dose groups (11.75%, 12.38%, and 17.63%, respectively) were greater than that of control (5.67%). The latter two groups were significantly different from that of control (P < 0.05, P < 0.01). The expressions of MGMT and XRCC1 decreased, and XRCC3 increased with the dose of VCM increased. DNA damage was correlated with the expression of XRCC3 (r = 0.438, P = 0.067).</p><p><b>CONCLUSION</b>VCM can cause DNA damage of liver cells with dose-response relationship. DNA damage repair enzymes take part in the repairing of DNA damage induced by VCM.</p>