Contact dermatitis is an unrecognized problem in the construction industry: Comparison of four different assessment methods.

BACKGROUND: A high contact dermatitis symptoms prevalence has been observed in Dutch construction workers. METHODS: Contact dermatitis was diagnosed by an expert panel using questionnaire data and photographs of 751 subjects' hands. A subset was evaluated by two occupational physicians. Their diagnoses were compared to those of the expert panel. In addition, two self-reported questionnaire-based assessment methods were compared to the expert panel evaluation. Associations between contact dermatitis and determinants were assessed using log-binomial regression analysis. RESULTS: Contact dermatitis prevalence was high: 61.4% (expert panel's diagnosis) and 32.9% (self-reported). Agreement between occupational physicians and the expert panel was low but increased after training. Washing hands with solvents and performing job-related tasks at home were related to contact dermatitis. CONCLUSIONS: Contact dermatitis prevalence among construction workers is high. Recognition of contact dermatitis by occupational physicians is poor but can be improved by training. Awareness of skin disorders should be raised.

Comparing REACH Chemical Safety Assessment information with practice-a case-study of polymethylmethacrylate (PMMA) in floor coating in The Netherlands.

On June 1st, 2007 the European regulation on Registration, Evaluation and Restriction of Chemical substances (REACH) came into force. Aim of the regulation is safe use of chemicals for humans and for the environment. The core element of REACH is chemical safety assessment of chemicals and communication of health and safety hazards and risk management measures throughout the supply chain. Extended Safety Data Sheets (Ext-SDS) are the primary carriers of health and safety information. The aim of our project was to find out whether the actual exposure to methyl methacrylate (MMA) during the application of polymethylmethacrylate (PMMA) in floor coatings as assessed in the chemical safety assessment, reflect the exposure situations as observed in the Dutch building practice. Use of PMMA flooring and typical exposure situations during application were discussed with twelve representatives of floor laying companies. Representative situations for exposure measurements were designated on the basis of this inventory. Exposure to MMA was measured in the breathing zone of the workers at four construction sites, 14 full shift samples and 14 task based samples were taken by personal air sampling. The task-based samples were compared with estimates from the Targeted Risk Assessment Tool (v3.1) of the European Centre for Ecotoxicology and Toxicology of Chemicals (ECETOC-TRA) as supplied in the safety assessment from the manufacturer. For task-based measurements, in 12 out of 14 (86%) air samples measured exposure was higher than estimated exposure. Recalculation with a lower ventilation rate (50% instead of 80%) together with a higher temperature during mixing (40°C instead of 20°C) in comparison with the CSR, reduced the number of underestimated exposures to 10 (71%) samples. Estimation with the EMKG-EXPO-Tool resulted in unsafe exposure situations for all scenarios, which is in accordance with the measurement outcomes. In indoor situations, 5 out of 8 full shift exposures (62%) to MMA were higher than the Dutch occupational exposure limit of 205mg/m3 (8h TWA), which equals the DNEL. For semi-enclosed situations this was 1 out of 6 (17%). Exposures varied from 31 to 367mg/m3. The results emphasize that ECETOC-TRA exposure estimates in poorly controlled situations need better underpinning.

Determinants of epoxy allergy in the construction industry: a case-control study.

BACKGROUND: Workers exposed to epoxy products are at risk of developing allergic contact dermatitis. OBJECTIVES: To compare workers throughout the German construction industry with and without skin allergy to epoxy resins, hardeners, and/or reactive diluents, and to investigate which determinants are related to the development of epoxy allergy. METHODS: A questionnaire was completed by 179 epoxy allergy cases, and 151 epoxy workers as controls. Crude and adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by the use of backwards stepwise logistic regression analysis. A multiple imputation approach was used to deal with missing data. RESULTS: Epoxy allergy was associated with an unusually high level of exposure to epoxy products [OR 2.13 (95%CI: 1.01-4.51)], wearing short sleeves or short trousers [OR 2.38 (95%CI: 1.03-5.52)], and not always using the correct type of gloves [OR 2.12 (95%CI: 1.12-4.01)]. A monotonic increasing risk was found with increasing exposure hours per week [OR 1.72 (95%CI: 1.39-2.14)]. Not using skin cream was inversely associated with epoxy allergy [OR 0.22 (95%CI: 0.08-0.59)]. Years working with epoxy products were inversely associated with epoxy allergy [OR 0.41 (95%CI: 0.27-0.61) per 10-year increase], suggesting a healthy worker survivor effect. CONCLUSIONS: Occupational epoxy allergy may be prevented by improving occupational hygiene behaviour and personal protection.

Validation of a questionnaire on hand hygiene in the construction industry.

INTRODUCTION: Construction workers are at risk of developing occupational contact dermatitis. Gloves, when used properly, may protect against chemicals and coarse materials. We investigated the prevalence and determinants of contact dermatitis in a population of Dutch construction workers and aimed at validating questionnaire items on hand hygiene. METHODS: A cross-sectional study was conducted at 13 construction sites, yielding data of 177 subjects (95% response rate). A questionnaire covering questions on hand hygiene and contact dermatitis symptoms was used. Agreement between workplace observations and a number of questionnaire items was assessed by calculating Cohen's kappa. Log-binomial regression analysis was used to assess the association between contact dermatitis and various hand hygiene-related determinants. RESULTS: The 1-year prevalence of self-reported contact dermatitis in our study sample was 46.9%. Multiple regression analysis showed a positive association with difficulties with hand cleaning (prevalence ratio [PR]: 1.26, 95% confidence interval [CI]: 1.05-1.52), hand contamination at the end of the working day (PR: 2.30, 95% CI: 1.14-4.65), and intensive hand cream use (PR: 2.07, 95% CI: 1.42-3.01). Observations of hand contamination, glove use, and glove types were found to agree well with the self-reported data from the questionnaire (Cohen's kappa's 0.75, 0.97, and 0.88). CONCLUSIONS: Self-reported contact dermatitis prevalence in construction workers was high and related to hand hygiene. A strong agreement was found between workplace observations and self-reported questionnaire data.

Skin symptoms in the construction industry: occurrence and determinants.

BACKGROUND: In the construction industry, a relatively high hand eczema prevalence can be expected due to exposure to irritating and allergenic agents. METHODS: As part of a regular program of voluntary medical examinations, a questionnaire including items on health symptoms and working circumstances is administered to construction industry personnel. We studied 152,200 male workers (response rate 52%). Associations between possible risk factors and self-reported skin symptoms and skin hypersensitivity were assessed using log-binomial regression analysis. RESULTS: Prevalence of skin symptoms on the hands was 25.4% among construction workers, 14.6% among office personnel. Nuisance due to dust exposure was the most important work-related determinant for skin symptoms [Prevalence Ratio (PR) 1.59, 95% confidence interval (CI): 1.55-1.63]. Cross-sectional findings were supported by longitudinal analyses in a study population subset. CONCLUSIONS: Skin symptoms are common among construction workers. Nuisance due to dust exposure was associated with higher prevalences of skin symptoms.

A screening programme on chronic solvent-induced encephalopathy among Dutch painters.

BACKGROUND: Long-term exposure to organic solvents may lead to chronic solvent induced encephalopathy (CSE) in painters. In combination with reduction of exposure, a workers' health surveillance programme was developed, resulting in a three-stage CSE screening procedure for early neurobehavioural changes possibly predicting chronic health effects. The screening consists of a questionnaire (Neurosymptom Screening Checklist 60, NSC-60), computerised neurobehavioural functioning testing (Neurobehavioural Evaluation System; NES2) and multidisciplinary differential diagnostic evaluation by experts (called 'Solvent Team'). Results from the screening were compared with the results of the 'care as usual' (CAU), in which symptomatic patients were referred directly to the Solvent Team by occupational physicians, general practitioners or medical specialists. Parallel to the screening programme, a legal ban on indoor use of solvent-based paints resulted in lower exposure to solvents. OBJECTIVE: To investigate the usefulness of the NSC-60 questionnaire as a screening tool for CSE among painters and to investigate the course of the number of CSE cases over the years as a potential consequence of improved prevention and control. RESULTS: From 1998 to 2004, more than 40,000 painters were invited to participate in a health surveillance programme including a periodical occupational health examination (PHE) and 50% did participate. Four percent (N=794) of these had a positive score on the NSC-60. The Solvent Team assessed 101 of these for CSE, which resulted in 27 CSE cases diagnosed. CAU during the same period of the surveillance (1998-2004) yielded 619 painters and 75 of these had the diagnosis CSE. After 2002 the number of CSE diagnosed cases dropped considerably and in 2004 only one case of CSE could be diagnosed. The substantially lower prevalence of CSE diagnosed cases in painters after 2002 might partly be explained as a result of a successful participation in the screening procedure of most prevalent CSE cases during the years 1998-2002. A second reason for the reduction of new diagnosed cases of CSE can be the effectiveness of the ban on indoor use of solvent-based paints resulting in lower exposure levels at work. CONCLUSION: The screening procedure is useful to screen for CSE among people taking part in the PHE programme. Control of CSE can be achieved by an integrated preventive approach with reduction of exposure and screening on early health effects.

Review of qualitative approaches for the construction industry: designing a risk management toolbox.

OBJECTIVES: This paper presents the framework and protocol design for a construction industry risk management toolbox. The construction industry needs a comprehensive, systematic approach to assess and control occupational risks. These risks span several professional health and safety disciplines, emphasized by multiple international occupational research agenda projects including: falls, electrocution, noise, silica, welding fumes, and musculoskeletal disorders. Yet, the International Social Security Association says, "whereas progress has been made in safety and health, the construction industry is still a high risk sector." METHODS: Small- and medium-sized enterprises (SMEs) employ about 80% of the world's construction workers. In recent years a strategy for qualitative occupational risk management, known as Control Banding (CB) has gained international attention as a simplified approach for reducing work-related risks. CB groups hazards into stratified risk 'bands', identifying commensurate controls to reduce the level of risk and promote worker health and safety. We review these qualitative solutions-based approaches and identify strengths and weaknesses toward designing a simplified CB 'toolbox' approach for use by SMEs in construction trades. RESULTS: This toolbox design proposal includes international input on multidisciplinary approaches for performing a qualitative risk assessment determining a risk 'band' for a given project. Risk bands are used to identify the appropriate level of training to oversee construction work, leading to commensurate and appropriate control methods to perform the work safely. CONCLUSION: The Construction Toolbox presents a review-generated format to harness multiple solutions-based national programs and publications for controlling construction-related risks with simplified approaches across the occupational safety, health and hygiene professions.

Exposure to respirable dust and crystalline silica in bricklaying education at Dutch vocational training centers.

BACKGROUND: Construction workers are educated at vocational training centers before they begin their working lives. Future bricklayers and their instructors are exposed to respirable dust and possibly to hazardous respirable crystalline silica from trial mortar. METHODS: Thirty-six personal air samples were collected at six training centers to estimate exposure to respirable dust for both students and teachers. A selection of 22 samples was analyzed for crystalline silica. RESULTS: Average respirable dust exposures ranged from 0.59 mg/m(3) for teachers to 1.45 mg/m(3) for students performing recycling and cleaning tasks. In 45% of the analyzed samples, respirable crystalline silica was detected. Exposure to silica remained below the Dutch OEL (75 microg/m(3)). Exposure was significantly less for teachers than for students. This effect was found in both types of vocational training centers present in the Netherlands. Dry sweeping, as performed at all locations in this study, contributed considerably to the exposure to respirable dust. A first step in reducing exposure to dust and silica at training centers would therefore be to avoid dry sweeping. The presence of a dust extraction system, although not optimally designed, also significantly lowered exposure. CONCLUSIONS: To assess a construction worker's lifetime exposure to respirable dust and crystalline silica, the vocational training period should also be taken into account. Several epidemiological studies have shown that time since first exposure can be an important risk factor for chronic health effects.

Exposure to wood dust among carpenters in the construction industry in the Netherlands.

Exposure to wood dust was measured among 26 carpenters at 13 building projects. Sampling days were chosen randomly. Individual tasks, based on technology applied and material used during a working day, were sampled separately. From these task-based measurements, 8 h time-weighted average concentrations were calculated. Sampling was performed in accordance with a protocol that was developed by the carpentry and furniture industry and which was especially designed for sampling of wood dust. Eight hours time-weighted average exposure to wood dust ranged from 0.8 to 11.6 mg m(-3) with a geometric mean (GM) of 3.3 mg m(-3) and a geometric standard deviation (GSD) of 2.1. The probability of exceedance of the OEL, when comparing the estimated concentrations against the Dutch OEL of 2 mg m(-3), was 75%. The highest exposures were measured during sawing of Cempanel sheets. Task-based measurements showed lowest exposures when working outdoors (n = 11, AM = 2.2 mg m(-3)), but even then 5 out of 11 task-based exposures exceeded 2 mg m(-3). Indoors the exposure was 5.2 mg m(-3) (AM, n = 29) and when working both indoors and outdoors exposure was 16.2 mg m(-3) (AM, n = 4). In conclusion, long-term average exposure to wood dust among carpenters at construction sites is more than 1.5 times the present occupational exposure limit of 2 mg m(-3). The estimated probability of exceedance of the OEL was 75% and a reduction of exposure with a factor 5 is needed to bring the probability of exceedance below 5%. It is intended to lower the exposure limit to 1 mg m(-3) by 1 January 2007. In that case the probability of exceedance of the OEL is 95% and a reduction of exposure with a factor 10 is needed to bring the probability of exceedance below 5%. This can be achieved by using alternative materials, preparation of building material in workshops equipped with exposure controls, alternative equipment and improved ventilation and good housekeeping.

Epoxy resins in the construction industry.

Epoxy resins are used as coatings, adhesives, and in wood and concrete repair. However, epoxy resins can be highly irritating to the skin and are strong sensitizers. Some hardeners are carcinogenic. Based on the results of earlier Dutch studies, an international project on "best practices,"--Epoxy Code--with epoxy products was started. Partners were from Denmark, Germany, the Netherlands, and the UK. The "Code" deals with substitution, safe working procedures, safer tools, and skin protection. The feasibility of an internationally agreed "ranking system" for the health risks of epoxy products was studied. Such a ranking system should inform the user of the harmfulness of different epoxies and stimulate research on less harmful products by product developers.

The conditions and perception of work during painting behind screening.

OBJECTIVE: This study attempted to reveal whether airborne solvent concentrations during painting behind screening are comparable to solvent concentrations during painting indoors, what factors potentially influence work conditions during painting behind screens, both positively and negatively, and what can be done to eliminate the disadvantages of screening. METHODS: Measurements of volatile organic compounds (VOC), climate, light, and noise were made at three sites during 1 day each. VOC were measured at another 10 sites, again during 1 day each. Questionnaires were sent to painters working in 305 firms. RESULTS: The results of the first series of measurements (exposure to VOC) ranged from 3.4 to 22.9 mg/m3 with a geometric mean of 11.7 and a geometric standard deviation of 2.1. This range was less than the level expected in well-ventilated rooms. In the second series of measurements, with a few exceptions, the concentrations of the individual compounds were below 1 mg/m3. In both series, the exposure index was generally < or = 0.05. The advantages of working behind screening were more certainty of work during the winter months, better temperature conditions, better quality of work, less draft, and less temperature fluctuation. CONCLUSIONS: Painting behind screening, as studied in this project, results in low exposure to VOC when compared with indoor situations. The main factors that need to be improved are temperature, lighting, view from the workplace, and ventilation.

Variability in quartz exposure in the construction industry: implications for assessing exposure-response relations.

The aims of this study were to determine implications of inter- and intraindividual variation in exposure to respirable (quartz) dust and of heterogeneity in dust characteristics for epidemiologic research in construction workers. Full-shift personal measurements (n = 67) from 34 construction workers were collected. The between-worker and day-to-day variances of quartz and respirable dust exposure were estimated using mixed models. Heterogeneity in dust characteristics was evaluated by electron microscopic analysis and electron spin resonance. A grouping strategy based on job title resulted in a 2- and 3.5-fold reduction in expected attenuation of a hypothetical exposure-response relation for respirable dust and quartz exposure, respectively, compared to an individual based approach. Material worked on explained most of the between-worker variance in respirable dust and quartz exposure. However, for risk assessment in epidemiology, grouping workers based on the materials they work on is not practical. Microscopic characterization of dust samples showed large quantities of aluminum silicates and large quantities of smaller particles, resulting in a D(50) between 1 and 2 microm. For risk analysis, job title can be used to create exposure groups, although error is introduced by the heterogeneity of dust produced by different construction workers activities and by the nonuniformity of exposure groups. A grouping scheme based on materials worked on would be superior, for both exposure and risk assessment, but is not practical when assessing past exposure. In dust from construction sites, factors are present that are capable of influencing the toxicological potency.

Dust control measures in the construction industry.

Quartz is a human carcinogen and a causative agent of silicosis. Exposure levels often exceed exposure limits in the construction industry. The need for effective control measures is high, but the complex structure of the construction industry, the variability in sources of exposure and the frequent changes of worksite makes it difficult to implement even simple and potentially effective control measures. The aim of this study was to evaluate the impact of control measures for reducing quartz dust exposure and to assess the extent of their use. Full-shift respirable dust measurements (n = 61) and short-term measurements among construction workers were performed and results of a questionnaire study among 1335 construction workers were analysed. Full-shift measurements showed respirable quartz exposure levels up to 63 times the maximum allowable concentration (MAC) value (0.075 mg/m(3)). More than half of the measurements were above the MAC value. Control measures were not very strongly associated with the full-shift exposure estimates, but the short-term measurements showed large reduction factors (>70%) when wet dust suppression or local exhaust ventilation was used. The effectiveness of control measures is potentially high, and a significant part of the construction worker population is indeed using them on a regular basis. Still, both the exposure study and questionnaire survey show that the use of respiratory protection is the most widely used preventive measure in the construction industry. Respiratory protection might not always reduce exposure sufficiently. Only the combined use of more than one control measure can reduce exposures to acceptable levels.

Lung cancer mortality in a Dutch cohort of asphalt workers: evaluation of possible confounding by smoking.

BACKGROUND: Using data from a Dutch cohort of workers in road construction and asphalt mixing companies, this article describes possible confounding of the association between exposure to bitumen fume and lung cancer mortality by smoking. METHODS: A retrospective cohort of 3,714 workers with at least one season of employment was identified. Semi-quantitative exposure to bitumen fume was assessed by a job-exposure matrix. Information on smoking habits was available for a sub-cohort of 1,138 workers, who underwent medical examinations by the occupational health services in the past. RESULTS: Smoking habits differed between occupational title groups and there was a positive association between cumulative exposure and smoking. Internal analyses using the non-exposed subjects as reference category, showed a positive association between semi-quantitative bitumen fume exposure and lung cancer risk. After adjusting for differences in smoking habits, all relative risks were reduced, but a weak positive association could still be observed. CONCLUSION: Confounding by smoking on the association between exposure to bitumen fume and lung cancer mortality is possible, although the positive trend (not statistically significant) for lung cancer mortality remained. Only a nested case-control study may allow proper treatment of potential (residual) confounding by smoking in this population.