Skin exposure to epoxy in the pipe relining trade - an observational study

Epoxy allergy, investigation of a modern industry

BACKGROUND

Five workers from an industry manufacturing various articles from carbon fibre reinforced epoxy plastics were referred to our department because of suspected occupational allergic contact dermatitis (OACD). When patch tested, four of them had positive reactions to components of epoxy resin systems (ERSs) that could explain their current skin problems. All of them had been working at the same workstation at a specially designed pressing machine, with operations including manually mixing epoxy resin with hardener. Multiple cases of OACD in the plant prompted an investigation including all workers with possible risk exposures at the plant.

OBJECTIVES

To investigate the prevalence of occupational dermatoses and contact allergies among the workers at the plant.

MATERIALS AND METHODS

Totally 25 workers underwent investigation that included a brief consultation with a standardized anamnesis and clinical examination followed by patch testing.

RESULTS

ERSs-related reactions were found in 7 of the 25 investigated workers. None of the seven had a history of previous exposure to ERSs and they are regarded as sensitized through work.

CONCLUSIONS

Twenty-eight percent of investigated workers showed reactions to ERSs. Of these the majority would have been missed if supplementary testing would not have been added to testing with the Swedish base line series.

Contact Dermatitis in Construction Workers in Northeastern Italian Patch Test Database Between 1996 and 2016

BACKGROUND

Contact dermatitis in construction workers (CWs) is frequent due to the widespread exposure to sensitizing substances and irritating agents and the wet and cold working conditions.

OBJECTIVE

Our objectives were to evaluate contact dermatitis characteristics among CWs who underwent patch test in northeastern Italy and to identify related allergens.

METHODS

Seven hundred ninety-five CWs were studied and their data were compared to 2.099 male white-collar workers. The associations between patch test results and occupations were assessed by multivariate logistic regression analysis. Incidence data were calculated from 1996 to 2016.

RESULTS

CWs with confirmed occupational dermatitis presented an increased risk to be sensitized to potassium dichromate [OR 3.1 (95%IC 2.0-4.8)], to thiurams [OR 8 .6 (95%IC 4.0-18.4)], and to epoxy resins [OR 12.7 (95%IC 6.1-26.4)]. Sensitization to chromate decreased significantly after 2004, following EU regulation of chromate content in concrete, while sensitization to epoxy resins and thiurams increased. The overall incidence of occupational contact dermatitis in CWs decreased significantly.

CONCLUSION

Our study demonstrated the effectiveness of EU regulations in reducing chromate sensitization in CWs and the overall incidence of occupational contact dermatitis. However, sensitization to other haptens is increasing, though improvement of protective measures is compulsory.

Occupational Dermatosis

PURPOSE OF REVIEW

The purpose of this review is to provide an update on occupational contact dermatitis including gaps in knowledge and practice. Occupational contact dermatitis is the most common occupational skin disease.

RECENT FINDINGS

New sources of exposure for known allergens and new allergens are continually being reported. Through clinical databases and surveillance systems, effects of prevention efforts or introduction of new allergens or new uses of known allergens can be monitored. Though the diagnostic process is clear, there are delays in workers seeking care. As early detection and intervention improves outcomes, screening should be implemented. Gaps in primary prevention in the workplace are identified and should be addressed to reduce the burden of disease. Surveillance systems support the prevention mandate. Understanding limitations of our knowledge and identifying gaps in practice can lead to initiatives to address research and practice needs and improve prevention of occupational dermatoses.

In vitro toxicity assessment of emitted materials collected during the manufacture of water pipe plastic linings

Objectives: US water infrastructure is in need of widespread repair due to age-related deterioration. Currently, the cured-in-place (CIPP) procedure is the most common method for water pipe repair. This method involves the on-site manufacture of a new polymer composite plastic liner within the damaged pipe. The CIPP process can release materials resulting in occupational and public health concerns. To understand hazards associated with CIPP-related emission exposures, an in vitro toxicity assessment was performed. Materials and Methods: Mouse alveolar epithelial and alveolar macrophage cell lines and condensates collected at 3 worksites utilizing styrene-based resins were utilized for evaluations. All condensate samples were normalized based on the major emission component, styrene. Further, a styrene-only exposure group was used as a control to determine mixture related toxicity. Results: Cytotoxicity differences were observed between worksite samples, with the CIPP worksite 4 sample inducing the most cell death. A proteomic evaluation was performed, which demonstrated styrene-, worksite-, and cell-specific alterations. This examination of protein expression changes determined potential biomarkers of exposure including transglutaminase 2, advillin, collagen type 1, perilipin-2, and others. Pathway analysis of exposure-induced proteomic alterations identified MYC and p53 to be regulators of cellular responses. Protein changes were also related to pathways involved in cell damage, immune response, and cancer. Conclusions: Together these findings demonstrate potential risks associated with the CIPP procedure as well as variations between worksites regarding emissions and toxicity. Our evaluation identified biological pathways that require a future evaluation and also demonstrates that exposure assessment of CIPP worksites should examine multiple chemical components beyond styrene, as many cellular responses were styrene-independent.

Outdoor manufacture of UV-Cured plastic linings for storm water culvert repair: Chemical emissions and residual

Storm water culverts are integral for U.S. public safety and welfare, and their mechanical failure can cause roadways to collapse. To repair these buried assets, ultraviolet (UV) light cured-in-place-pipes (CIPP) are being installed. Chemical emission and residual material left behind from the installation process was investigated in New York and Virginia, USA. Samples of an uncured resin tube and field-cured styrene-based resin CIPPs were collected and analyzed. Also collected were air and water samples before, during, and after installations. Chemicals were emitted into air because of the installation and curing processes. Particulates emitted into the air, water, and soil contained fiberglass, polymer, and contaminants, some of which are regulated by state-level water quality standards. The uncured resin tube contained more than 70 chemical compounds, and 19 were confirmed with analytical standards. Compounds included known and suspected carcinogens, endocrine disrupting compounds, hazardous air pollutants, and other compounds with little aquatic toxicity data available. Compounds (14 of 19 confirmed) were extracted from the newly installed CIPPs, and 11 were found in water samples. Aqueous styrene (2.31 mg/L), dibutyl phthalate (12.5 μg/L), and phenol (16.7 μg/L) levels exceeded the most stringent state water quality standards chosen in this study. Styrene was the only compound that was found to have exceed a 48 h aquatic toxicity threshold. Newly installed CIPPs contained a significant amount volatile material (1.0 to > 9.0 wt%). Recommendations provided can reduce chemical emission, as well as improve worksite and environmental protection practices. Recommended future research is also described.

Skin exposure to epoxy chemicals in construction coating, assessed by observation, interviews, and measurements

BACKGROUND

Epoxy resin systems (ERSs) are among the leading causes of occupational allergic contact dermatitis.

OBJECTIVES

To identify riskful exposures and sources of skin exposure, and to quantify skin exposure to diglycidyl ether of bisphenol A (DGEBA) epoxy monomer, in construction coating work.

METHODS

Skin exposure to epoxy chemicals was studied in 5 coating companies through (a) interviews and visual observation, (b) quantifying DGEBA on 12 workers' skin by tape-stripping, (c) measuring DGEBA on 23 surfaces by wipe-sampling, and (d) quantifying DGEBA in new sewage pipe. Acetone extracts of the tapes, wipes and sawdust from a newly hardened sewage pipe were analysed by gas chromatography/mass spectrometry.

RESULTS

Identified riskful exposures were, for example, mixing ERSs, handling coating pots, and working above shoulder level. Epoxy stains on, for example, tools, equipment and clothing were seen in all workplaces. Protective gloves were of varying quality, and were not always suitable for chemicals. The amount of DGEBA on the workers' skin varied considerably. All screened tool handles were contaminated. Two-day-old epoxy sewage pipe contained 3.2% DGEBA.

CONCLUSIONS

Construction coating entails skin contact with ERSs directly and via contaminated surfaces, personal protective equipment, and recently hardened epoxy materials. Observation is a useful method for assessing skin exposure in coating work.

Contamination of skin and surfaces by cobalt in the hard metal industry

BACKGROUND

It is well known that hard metal workers have historically been affected by contact allergy to cobalt. Knowledge is sparse about occupational skin exposure to cobalt, in terms of skin doses and sources of exposure, which could be used to improve protection of workers.

OBJECTIVES

To improve knowledge about skin doses and sources of skin exposure to cobalt within hard metal production, thereby facilitating better protection of workers.

METHODS

Forty workers were sampled on the index finger by acid wipe sampling after 2 hours of work. The samples were analysed with inductively coupled plasma mass spectrometry. Cobalt spot testing was performed in the work environment.

RESULTS

The highest skin doses were found among raw material workers. Skin doses among other production workers were also significant. Most office workers had low, but measurable, levels of cobalt on the skin. Glove use varied between workers. Cobalt was found on production equipment, on items in the canteen area, and on handles and buttons throughout the company.

CONCLUSIONS

Cobalt skin doses were prominent, and originated from contact with raw materials, sintered materials, and contaminated surfaces. Cobalt was present on surfaces outside production areas. Companies need to identify and reduce skin exposure for protection of workers.