Occupational acro-osteolysis pertains to bone resorption of the distal phalanges of the hands and feet among workers with vinyl chloride exposure. We report the case of a Filipino man with osteolysis of the distal phalanges of the hands initially considered to have systemic sclerosis. The patient had gradual shortening of the fingers, thickening of the skin over the extremities, and hypopigmented patches over a span of more than 20 years. His lower extremities presented with non-pitting edema, skin thickening, and neuropathy, without shortening of the digits. Difficulty of ambulation was apparent due to the development of feet inversion. Radiographic findings of the hands and feet included resorption of distal phalanges, erosive and sclerotic changes, and narrowed joint spaces. Other conditions considered were Hansen’s disease, skeletal tuberculosis, and diabetic neuropathic arthropathy, which were eventually ruled out. The final diagnosis was occupational acro-osteolysis secondary to vinyl chloride exposure. The patient underwent serial total contact casting of the bilateral lower extremities to relieve bipedal edema and to reposition the feet. This case emphasizes the significance of investigating a patient’s occupational history and highlights a rare sequela of exposure to a commonly used chemical agent in the manufacture of polyvinyl chloride products.
bone resorption ; vinyl chloride ; Filipino

OBJECTIVES: It is the objective of this research to identify the variation of thiodiglycolic acid (TdGA) in urine with vinyl chloride monomer (VCM) exposure levels through methylation. METHODS: After rats were exposed to vinyl chloride monomer of 4 levels, 0 mg/m3, 50 mg /m3, 150 mg/m3, 500 mg/m3, respectively, of which urine was sampled in each sampling time of 0 hour, 2 hours, 4 hours, 8 hours, 16 hours, 24 hours, 36 hours, 48 hours. After urine had been methylated with diazomethane in the preliminary experiment and the peak of 146 m/z had been verified, the main experiment was done. RESULTS: In the variation of TdGA with sampling times, concentration of TdGA increased rapidly in 4 hours and then decreased after 8 hours. When the variation of urinary .TdGA concentration in urine according to exposure level of VCM was verified through Kruskal-Wallis statistical method at each sampling time, the significant increment with the exposure levels at 2 hours, 4 hours, 8 hours after exposure was clarified. CONCLUSION: TdGA concentration in urine with increment of VCM exposure level increased, especially significantly at 2 hours, 4 hours, 8 hours of sampling time.
Animals ; Diazomethane ; Methylation ; Rats* ; Vinyl Chloride*

OBJECTIVES: The study was performed to investigate the changes of urinary thiodiglycolic acid (TDGA) concentration in workers exposed to vinyl chloride monomer (VCM) according to the time of sampling urine. METHODS: The personal exposure to airborne VCM was assessed and urinary TDGA concentration was sampled in 31 workers employed in a VCM and polyvinyl chloride (PVC) manufacturing factory. Urinary TDGA was sampled three times: before the start of the shift after 3 days off (TDGA1), after the end of the first-day shift (TDGA2) and before starting the following day shift after completing the oneday shift (TDGA3). Urinary TDGA in 30 workers who had not been exposed to airborne VCM was sampled after the end of the shift. A gas chromatography/pulsed flame photometric detector (GC/PFPD) was utilized to analyze TDGA concentration in urine after the urine was methylated with trimethylsilyldiazomethane(2.0M in diethyl ether). RESULTS: The creatinine level was 0.179+/-0.271 mg/g in the control workers and 0.218+/-0.443 mg/g in the workers before the start of the shift after 3 days off (TDGA1), showing no significant difference (p=0.7035). Urine samples were compared according to sampling time in order to investigate the change of urinary TDGA concentration in the case of continuous exposure to airborne VCM. In VCM-exposed workers, urinary creatinine concentration was 0.434+/-0.623 mg/g in TDGA2 and 0.767+/-1.056 mg/g in TDGA3, which indicated a gradual but significant increase (p=0.024). In terms of the statistical correlation between airborne VCM and urinary TDGA to evaluate exposure dose per day, of the three urinary TDGA concentrations, TDGA3 showed the highest degree of regression (R(2)=0.4215) with 8h-TWA airborne VCM concentration. CONCLUSION: Based on this result, the excretion half-life of urinary TDGA was assumed to be less than 3 days, because the concentration of urinary TDGA at 3 days after exposure to airborne VCM was decreased to the level of urinary TDGA concentration in the control workers. The concentration of urinary TDGA increased in the case of continuous shift, due to the accumulation of residual metabolites of TDGA. It was considered that TDGA3 can be applied as a useful biological index to evaluate the exposure dose of airborne VCM during one day because TDGA3 showed the highest correlation with the exposure dose of airborne VCM in the previous shift day.
Creatinine ; Half-Life ; Humans ; Polyvinyl Chloride ; Vinyl Chloride*

OBJECTIVETo establish a rapid determination method with gas chromatography-mass spectrometer (GC-MS) for thiodiglycolic acid (TDGA), a vinyl chloride (VCM) biomarker.

METHODSA high- sensitivity determination method was established using a moderate methyl esterification instead of methyl esterification of highly toxic diazo reaction.

RESULTSThe standard curve regression linear equation of the method was: y=8460.5x-4758.2, the linear coefficient was 0.999 7, the minimum quantity concentration was 2.0 µg/L, the range of precision value was 0.81%-2.38%, and the average recovery of standard addition was 99.0%-102.9%.

CONCLUSIONThis method reduces the risk of traditional methyl esterification, improves the determination sensitivity compared with the GC-FPD method, and meets the determination requirement of TDGA.

Gas Chromatography-Mass Spectrometry ; Humans ; Thioglycolates ; urine ; Vinyl Chloride

OBJECTIVETo explore the relationship between genetic polymorphism of P53, P21, CCND1 and susceptibility of chromosomal damage induced by vinyl chloride monomer (VCM).

METHODS183 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).

RESULTSThe 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.

CONCLUSIONAmong 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.

Cell Cycle Checkpoints ; Humans ; Micronucleus Tests ; Occupational Exposure ; Polymorphism, Genetic ; Vinyl Chloride

OBJECTIVETo screen out serum differential proteins between vinyl chloride monomer (VCM)-exposed workers and healthy controls by proteomics and analyze the functions of differential proteins, and to provide a basis for elucidating the pathogenesis of diseases caused by VCM exposure and searching for the protein biomarkers.

METHODSFasting venous blood was collected from 125 VCM-exposed workers and 40 healthy controls according to accumulated exposure doses. Proteins were precipitated by acetone precipitation. These proteins were identified by 2D-nano LC-ESI-TOF/MS and quantified by isobaric tags for relative and absolute quantitation. The functions of differential proteins were analyzed by gene ontology.

RESULTSA total of 596 proteins were identified, including 194 quantified proteins. There were 21 differential proteins according to the screening criteria (19 upregulated proteins and 2 downregulated proteins), including complement, apolipoprotein, and glycoprotein. The functions of these differential proteins were binding, enzyme regulator activity, catalytic activity, and transporter activity, and they were involved in the biological processes including immune system process and response to stimulus.

CONCLUSIONThe complement, apolipoprotein, and glycoprotein identified in the proteomics may be related to liver injury caused by VCM exposure, and they could be used as candidate protein biomarkers of diseases caused by VCM exposure.

Biomarkers ; blood ; Blood Proteins ; analysis ; Humans ; Liver ; injuries ; Occupational Exposure ; Proteins ; metabolism ; Proteomics ; Vinyl Chloride ; toxicity

BACKGROUND: This study was conducted to evaluate vinly chloride exposure in vinyl chloride and poly vinyl chloride manufacturing factories. The object of this study was compare two different type of air sampling method that of, NIOSH and OSHA recommended and Investigate quantitative correlation between level of vinyl chloride exposure and urinary thiodiglycolic acid excretion. METHODS: Air sampling was conducted by two method and sampling mediums were located at workers breathing zone in the same location. Sampling mediums were changed in 60 minute interval and sampling pumps were recalibrated at the same time. Urine was collected before and end of shift were stored frozen and determined by GC/FID analysis. RESULTS: In NIOSH method, time weighted average was 3.562 +/- 2.898 ppm and OSHA method time weighted average was 4.051 +/- 3.700 ppm. Concentration of urinary TdGA in before shift was 0.527 +/- 0.828 g/g creatinine and end of shift was 4.190 +/- 7.665 mg/g creatinine. Difference of urinary TdGA between end of shift to before shift was 3.662 +/- 7.865 mg/g creatinine. In NIOSH method, correlation coefficient between 8hour-time weighted average (8hrs-TWA) and urinary concentration of TdGA was r=0.666. and last period vinyl chloride level (6th-TWA) and urinary TdGA concentration was r=0.972. In OSHA method, correlation coefficient between last period vinyl chloride level (6th-TWA) and urinary concentration of TdGA was r=0.976 and this was highest value. CONCLUSION: There was no statistically significant difference in NIOSH method and. OSHA method. A correlation were found between level of vinyl chloride exposure and urinary thiodiglycolic acid excretion. Also, vinyl chloride exposure had significantly effected on the urinary thiodiglycolic acid excretion.
Creatinine ; National Institute for Occupational Safety and Health (U.S.) ; Respiration ; United States Occupational Safety and Health Administration ; Vinyl Chloride*

Objective: To investigate the detection of occupational health for vinyl chloride workers in Tianjin. Methods: In this study, we have collected data from 7 companies with vinyl chloride hazards in 16 districts of Tianjin. Finally, the occupational health surveillance data of 478 vinyl chloride-exposed workers were included in the analysis. Quantitative data was tested for normality. If the data conforms to the normal distribution, using the Mean±SD for statistical description, and t test for statistical analysis. If the data does not conform to the normal distribution, using Median (Q(1), Q(100)) for statistical description, rank sum test for statistical analysis. The qualitative data was described by composition ratio, and the chi-square test was used for statistical analysis. The logistic regression was used to assess the impact on suspected occupational disease and occupational contraindication from personal general conditions, occupational history, company information. Results: The abnormal detection rate of vinyl chloride monomer workers in Binhai New Area was higher than that in other areas (χ(2)=5.20, P=0.023). The abnormal detection rate of vinyl chloride monomer workers in non manufacturing industries was higher than that in manufacturing industries (χ(2)=7.74, P=0.005). The abnormal detection rate of vinyl chloride monomer workers in domestic enterprises was higher than that in foreign invested enterprises (χ(2)=22.38, P<0.01). Compared with the normal group of vinyl chloride monomer workers, the abnormal group of workers was older and had longer working years, The difference was statistically significant (Z=-3.32, -3.54, P=0.001, <0.01). The employer of vinyl chloride monomer workers is in Binhai New Area, the economic type is domestic funded enterprise, the industry is classified as non manufacturing industry, the age is more than 40 years old, and the length of service is more than 20 years old, which is the influencing factor for workers to detect abnormalities (OR=1.875, 95%CI: 1.279~2.749; OR=1.657, 95%CI: 1.071~2.563; OR=3.562, 95%CI: 2.057~6.170; OR=2.166, 95%CI: 1.245~3.768; OR=1.968, 95%CI: 1.345~2.879, all P<0.05) . Conclusion: To protect the health of workers and prevent occupational diseases, the management of vinyl chloride exposure on production process, especially in domestic enterprise, should be improved. Also, better occupational health surveillance should be provided to female workers.
Humans ; Female ; Adult ; Young Adult ; Vinyl Chloride ; Occupational Health ; Occupational Exposure ; Occupational Diseases/epidemiology* ; Industry

The usage of vinyl chloride and trichloroethylene in China has been increasing year by year, and they have been detected in both drinking water and environmental water, making them important environmental pollutants. Based on the latest research results on the health effects of vinyl chloride and trichloroethylene, the newly issued, "Standards for Drinking Water Quality (GB5749-2022)" in China has adjusted the standard limit of vinyl chloride from 0.005 mg/L to 0.001 mg/L and the standard limit of trichloroethylene from 0.07 mg/L to 0.02 mg/L. This article analyzed and discussed the relevant technical contents for determining the above standard limits, including the levels and exposure conditions of vinyl chloride and trichloroethylene in the water environment, health effects, derivation of safety reference values, and determination of hygiene standard limits. Suggestions were also made for the implementation of this standard.
Humans ; Vinyl Chloride/analysis* ; Trichloroethylene/analysis* ; Drinking Water ; Environmental Pollutants ; China ; Water Pollutants, Chemical/analysis*

In order to develop questionnaire estimating vinyl chloride monomer(VCM) exposure levels, to reset selection criteria for detailed tests, to measure current VCM exposure levels, to evaluate the mutagenic effects of VCM exposures and to develop multiphasic screening method of PVC- or VCM-handling workers, VCM concentrations of work environments were measured and tentative self-administrative questionnaire, physical examination, sister chromatid exchange(SCE) test and some clinical chemical test were applied to 195 men who had been handling VCM or PVC(Exposed Group) and 37, in the same factories without exposure to VCM or in polyethylene- or polypropylene-related factories(Control Group). Mean VCM concentrations of work environments were 0.268+/-0.183 ppm under PVC synthesis processes, 0.160+/-0.200 ppm under VCM synthesis process, 0.076+/-0.111 ppm under PVC pipe producing processes, 0.090+/-0.108 ppm under PVC wall paper, sheet, or film producing processes, 0.071+/-0.051 ppm under PVC floor producing processes, 0.243+/-0.250 ppm under PVC sash producing processes, and 0.020+/-0.031 ppm under triming process. VCM levels of work environments under manual resin mixing processes (0.209+/-0.168 ppm)were higher than those of the others (0.209+/-0.168 ppm) (p-value<0.05). There was no VCM-related symptoms, the positive response rates of which were higher in the Exposed Group. Overall abnormal rate in clinical chemistry test of the Exposed Group was higher than that of the Control Group, but due to extermely low exposure level of exposure group and to small sample size of the Control Group, no statistical significance was found(p-value>0.05). SCE frequencies of the Exposed Group were significantly higher than those of Contorl Group(p-value<0.05) and those of test-abnormal persons were higher than those of test-normal persons. SCE frequencies linearly increased with not only current but also cumulative VCM exposure levels(p-value<0.05). These results suggest that adverse health effect may ensue from VCM exposure to as low as 1 ppm. But SCE frequencies had no statistically significant correlation with drinking amounts, smoking amoutns, or radiation dose equivalents. Questionnaire was revised by referring to these results and formula estimating cumulative VCM exposure levels based on occupational history in questionnaire were made. In addition, were presented methods evaluating work environments and multiphasic screening test for PVC workers.
Chromatids ; Clinical Chemistry Tests ; Drinking ; Humans ; Male ; Multiphasic Screening* ; Patient Selection ; Physical Examination ; Polyvinyl Chloride* ; Polyvinyls* ; Questionnaires ; Sample Size ; Siblings ; Sister Chromatid Exchange ; Smoke ; Smoking ; Vinyl Chloride*