ABSTRACT
OBJECTIVE: To analyze the skills of using dust mask in the dust-exposed workers in civil metal ship manufacturing enterprises. METHODS: A total of 123 dust-exposed workers in a civil metal ship manufacturing enterprise were selected as the research subjects using convenience sampling method. Dust Mask Using Situation and Maintenance Questionnaire was used to investigate the use of dust masks, and the tightness of using dust mask was measured by the tightness tester. RESULTS: The median, and the 0 th-100 th percentiles[M(P_0-P_(100))] of the dust mask use time in the workers was 3.0(1.0-3.0) months, and the M(P_0-P_(100)) of filter element use time was 1.0(0.5-2.0) workdays. The subjects did not disinfect the masks after use. Only 36.6%(45/123) of workers regularly cleaned dust masks during use. There was 62.6%(77/123) of workers who failed to correctly perform negative pressure air tightness check by themselves. A total of 112 workers carried out tightness test, and the pass rate of those who passed the tightness test for the first time was 62.5%(70/112). The median, and the 25 th and 75 th percentiles [M(P_(25), P_(75))] of fit factor(FF) in the 70 qualified workers was 835.0(503.0, 1 635.0). After retests, the overall tightness test pass rate was 66.1%(74/112), and the M(P_(25), P_(75)) of FF in the 74 qualified workers was 786.0(477.7, 1 532.2). The reasons for failure of tightness test were the mismatch of the mask and face size, wrong wearing methods and long beard. CONCLUSION: Some of the dust-exposed workers in the civil metal ship manufacturing enterprises did not use the dust mask correctly. The dust mask configuration and the use and maintenance training should be strengthened, and the tightness test should be carried out regularly to improve workers′ skills in using dust masks.
ABSTRACT
OBJECTIVE: To explore the distribution characteristics of single nucleotide polymorphism(SNP) rs7072793 and rs3118470 in the 5′ flanking region of(cluster of differentiation 25, CD25) gene in Han males in the naturally high radiation background area(HBRA). METHODS: A random sampling method was used to select 48 and 51 healthy Han males from Tangkou town(HBRA group) in Yangjiang City and Hengpo town(control group) in Enping City, respectively, as the study subjects. The molecular mass array method was used to classify the genotype of the SNP sites rs7072793 and rs3118470 of CD25 gene in these subjects. The distribution difference of the alleles and genotypes was analyzed in individuals of these two groups. The allele frequency of HBRA population was compared with the distribution data of different populations in the Human Genome Project.RESULTS: The distribution of allele frequencies of rs7072793 and rs3118470 in both groups were consistent with the H-W equilibrium law of genetics(all P>0.05). In the HBRA group, variant allele C(58.3%) and genotype TC(50.0%) were dominant at rs7072793, wild-type allele T(55.2%) and genotype TC(56.2%) were dominant at rs3118470. There was no significant difference in the allele and genotype distributions between these two groups(all P>0.05). There was a difference of rs7072793 in the HBRA group compared to that of African and European populations, and rs3118470 in the HBRA group compared with the allele distribution frequencies in Africa, Europe and America populations(all P<0.05). CONCLUSION: In the male population of Han nationality in Yangjiang HBRA area, the alleles of rs7072793 and rs3118470 in the 5′ flanking region of CD25 gene were mainly C and T, respectively, and the genotypes were mainly TC. These two loci may have high genetic variability.