Individual, occupational, and workplace correlates of occupational health and safety vulnerability in a sample of Canadian workers

Objective: To describe OH&S vulnerability across a diverse sample of Canadian workers.
Methods: A survey was administered to 1,835 workers employed more than 15 hrs/week in workplaces with at least five employees. Adjusted logistic models were fitted for three specific and one overall measure of workplace vulnerability developed based on hazard exposure and access to protective OH&S policies and procedures, awareness of employment rights and responsibilities, and workplace empowerment.
Results: More than one third of the sample experienced some OH&S vulnerability. The type and magnitude of vulnerability varied by labor market sub-group. Younger workers and those in smaller workplaces experienced signficantly higher odds of multiple types of vulnerability. Temporary workers reported elevated odds of overall, awareness- and empowerment-related vulnerability, while respondents born outside of Canada had significantly higher odds of awareness vulnerability.
Conclusion: Knowing how labor market sub-groups experience different types of vulnerability can inform better-tailored primary prevention interventions.

Ocular exposure to UV-B in sunlight: the Melbourne Visual Impairment Project model

Quantification of ocular exposure to ultraviolet-B radiation (UV-B) has become an important public health issue, with reports that the ozone layer is being depleted worldwide. Ocular exposure to UV-B is determined by ambient UV-B levels, the duration of outdoor exposure, the proportion of ambient UV-B that reaches the eye, and the use of ocular protection. We have developed a simplified model for quantifying lifetime ocular UV-B exposure that can be used in large epidemiological surveys. Exposure to UV-B is assessed and quantified using a model based on personal exposure over the six summer months. Data available for a population-based sample of 1150 people in the age range 40-98 years revealed a distribution in average annual lifetime ocular UV-B exposure similar to that reported in a previous study on which this model is based, and also demonstrate that people can recall lifetime personal behaviour related to ocular protection. It takes 12 minutes on average to collect these data. This model can be employed by researchers worldwide for uniform assessment of ocular UV-B exposure.

Association between distressing non-work-related events and occupational injuries

The following is a report on a case-control study whose objective was to investigate the association between distressing non-work-related events and occupational injures. Ninety three injured workers (cases) were matched with 372 non-injured controls in a large metallurgical factory in southeastern Brazil. Exposure to distressing non-work-related events was measured through a questionnaire focusing on situations pertaining to personal problems unrelated to work activities. The data were analyzed by adjusting a conditional logistic regression model, where occurrence of the work injury was the dependent dichotomous variable and answers from the questionnaire were independent continuous variables. The analysis showed an association between some distressing non-work-related events and occupational injuries. These findings imply expanding the horizon of preventive measures used in targeting. work injuries which have traditionally been focused on the control of strictly workplace risks.

Using the current Brazilian value for the biological exposure limit applied to blood lead level as a lead poisoning diagnostic criterion

Tradicionalmente, os limites de tolerância biológica são utilizados exclusivamente para a promoção e a preservação da saúde dos trabalhadores, não sendo aplicados com fins diagnósticos. Entretanto, com relação a algumas intoxicações profissionais, o assunto é polêmico. Neste artigo, defende-se a utilização do limite de tolerância aplicado atualmente no Brasil à plumbemia como um critério importante para a realização do diagnóstico da intoxicação profissional pelo chumbo. Argumenta-se que, em oposição ao tradicional critério clínico, deve-se abordar o problema do diagnóstico da intoxicação pelo chumbo sob um ponto de vista epidemiológico, utilizando-se o atual valor do limite de tolerância para a plumbemia como um marcador de risco relativo significativamente aumentado.

Reduced allergic lung inflammation in rats following formaldehyde exposure: Long-term effects on multiple effector systems

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Suggestion of an inverse relationship between perception of occupational risks and work-related injuries

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Stressful life events and occupational accidents

Objective: The purpose of this study was to examine the association between stressful life events and occupational accidents. Methods: This was a population-based case-control study, carried out in the city of Botucatu, in southeast Brazil. The cases consisted of 108 workers who had recently experienced occupational accidents. Each case was matched with three controls. The cases and controls answered a questionnaire about recent exposure to stressful life events. Results: Reporting of environmental problems, being a victim of assault, not having enough food at home and nonoccupational fatigue were found to be risk factors for work-related accidents with estimated incidence rate ratios of 1.4 [95% confidence interval (95% CI) 1.1-1.7], 1.3 (95% CI 1.1 1-1.7), 1.3 (95% CI 1.1-1.6), and 1.4 (95% CI 1.2-1.7) respectively. Conclusions: The findings of the study suggested that nonwork variables contribute to occupational accidents, thus broadening the understanding of these phenomena, which can support new approaches to the prevention of occupational accidents.

Firefighters' noise exposure: a literature review

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Musculoskeletal disorders in upper limbs in dental students: exposure level to risk factors

Aim: This study assessed the risk factors of undergraduate students to develop musculoskeletal disorders (MSD) in the upper limbs, regarding gender, type of dental clinical procedure, mouth region treated, and the four-handed dentistry practice. Methods: Dental students enrolled in the 8th semester in the Araraquara School of Dentistry, UNESP, Brazil, were photographed while practicing 283 dental procedures. The Rapid Upper Limb Assessment (RULA) method was used to evaluate the working postures of each student. The photographs were evaluated and a final risk score was attributed to each analyzed procedure. The prevalence of risk factors of developing MSD was estimated by point and by 95% confidence interval. The association between the risk factor of developing disorders and variables of interest were assessed by the chi-square test with a significance level of 5%. Results: The risk factors of developing MSD were high, regarding most dental procedures performed by the undergraduate students (score 5: 7.07%, CI95%: 4.08- 10.06%; score 6: 62.54%, CI95%: 56.90-68.18%). There was no significant association between the RULA final score and gender (p=0.559), and type of dental procedure (p=0.205), and mouth regions by arch (p=0.110) or hemi-arch (p=0.560), and the use of four-handed dentistry (p=0.366). Conclusions: It can be concluded that gender, type of dental clinical procedure, mouth region treated, and practice of four-handed dentistry did not influence the risk of developing MSD in the upper limbs among the dental students evaluated; however, they are at a high risk of developing such disorders.

Muskuloskeletal disorders in upper limbs in dental students: exposure level to risk factors

Aim: This study assessed the risk factors of undergraduate students to develop musculoskeletaldisorders (MSD) in the upper limbs, regarding gender, type of dental clinical procedure, mouthregion treated, and the four-handed dentistry practice. Methods: Dental students enrolled in the8th semester in the Araraquara School of Dentistry, UNESP, Brazil, were photographed whilepracticing 283 dental procedures. The Rapid Upper Limb Assessment (RULA) method was usedto evaluate the working postures of each student. The photographs were evaluated and a finalrisk score was attributed to each analyzed procedure. The prevalence of risk factors of developingMSD was estimated by point and by 95% confidence interval. The association between the riskfactor of developing disorders and variables of interest were assessed by the chi-square test witha significance level of 5%. Results: The risk factors of developing MSD were high, regardingmost dental procedures performed by the undergraduate students (score 5: 7.07%, CI95%: 4.08-10.06%; score 6: 62.54%, CI95%: 56.90-68.18%). There was no significant association betweenthe RULA final score and gender (p=0.559), and type of dental procedure (p=0.205), and mouthregions by arch (p=0.110) or hemi-arch (p=0.560), and the use of four-handed dentistry (p=0.366).Conclusions: It can be concluded that gender, type of dental clinical procedure, mouth regiontreated, and practice of four-handed dentistry did not influence the risk of developing MSD in theupper limbs among the dental students evaluated; however, they are at a high risk of developingsuch disorders.(AU).

P300 in workers exposed to occupational noise

The harm upon the central auditory pathways of workers exposed to occupational noise has been scarcely studied. Objective: To assess the central auditory pathways by testing the long latency auditory evoked potentials (P300) of individuals exposed to occupational noise and controls. Method: This prospective study enrolled 25 individuals with normal hearing thresholds. The subjects were divided into two groups: individuals exposed to occupational noise (13 subjects; case group) and individuals not exposed to occupational noise (12 subjects; control group). The P300 test was used with verbal and non-verbal stimuli. Results: No statistically significant differences were found between ears for any of the stimuli or between groups. The groups had no statistically significant difference for verbal or non-verbal stimuli. Case group subjects had longer latencies than controls. In qualitative analysis, a greater number of altered P300 test results for verbal and non-verbal stimuli was seen in the case group, despite the absence of statistically significant differences between case and control subjects. Conclusion: Individuals exposed to high sound pressure levels had longer P300 latencies in verbal and non-verbal stimuli when compared to controls.

Acute respiratory syndrome after inhalation of waterproofing sprays: a posteriori exposure-response assessment in 102 cases

Waterproofing agents are widely used to protect leather and textiles in both domestic and occupational activities. An outbreak of acute respiratory syndrome following exposure to waterproofing sprays occurred during the winter 2002-2003 in Switzerland. About 180 cases were reported by the Swiss Toxicological Information Centre between October 2002 and March 2003, whereas fewer than 10 cases per year had been recorded previously. The reported cases involved three brands of sprays containing a common waterproofing mixture, that had undergone a formulation change in the months preceding the outbreak. A retrospective analysis was undertaken in collaboration with the Swiss Toxicological Information Centre and the Swiss Registries for Interstitial and Orphan Lung Diseases to clarify the circumstances and possible causes of the observed health effects. Individual exposure data were generated with questionnaires and experimental emission measurements. The collected data was used to conduct numeric simulation for 102 cases of exposure. A classical two-zone model was used to assess the aerosol dispersion in the near- and far-field during spraying. The resulting assessed dose and exposure levels obtained were spread on large scales, of several orders of magnitude. No dose-response relationship was found between exposure indicators and health effects indicators (perceived severity and clinical indicators). Weak relationships were found between unspecific inflammatory response indicators (leukocytes, C-reactive protein) and the maximal exposure concentration. The results obtained disclose a high interindividual response variability and suggest that some indirect mechanism(s) predominates in the respiratory disease occurrence. Furthermore, no threshold could be found to define a safe level of exposure. These findings suggest that the improvement of environmental exposure conditions during spraying alone does not constitute a sufficient measure to prevent future outbreaks of waterproofing spray toxicity. More efficient preventive measures are needed prior to the marketing and distribution of new waterproofing agents.

Mortality from neurodegenerative disease and exposure to extremely low-frequency magnetic fields: 31 years of observations on Swiss railway employees

AIMS: The objective of the present study was to investigate the relationship between extremely low-frequency magnetic field (ELF-MF) exposure and mortality from several neurodegenerative conditions in Swiss railway employees. METHODS: We studied a cohort of 20,141 Swiss railway employees with 464,129 person-years of follow-up between 1972 and 2002. For each individual, cumulative exposure was calculated from on-site measurements and modelling of past exposure. We compared cause-specific mortality in highly exposed train drivers (mean exposure: 21 microT) with less exposed occupational groups (for example station masters: 1 microT). RESULTS: The hazard ratio for train drivers compared to station masters was 1.96 [95% confidence interval (CI) = 0.98-3.92] for senile dementia and 3.15 (95% CI = 0.90-11.04) for Alzheimer's disease. For every 10 microT years of cumulative exposure senile dementia mortality increased by 5.7% (95% CI = 1.3-10.4), Alzheimer's disease by 9.4% (95% CI = 2.7-16.4) and amyotrophic lateral sclerosis by 2.1% (95% CI = -6.8 to 11.7). There was no evidence for an increase in mortality from Parkinson's disease and multiple sclerosis. CONCLUSIONS: This study suggests a link between exposure to ELF-MF and Alzheimer's disease and indicates that ELF-MF might act in later stages of the disease process.

Leukaemia, brain tumours and exposure to extremely low frequency magnetic fields: cohort study of Swiss railway employees

AIMS: To investigate the relationship between extremely low frequency magnetic field (ELF-MF) exposure and mortality from leukaemia and brain tumour in a cohort of Swiss railway workers. METHODS: 20,141 Swiss railway employees with 464,129 person-years of follow-up between 1972 and 2002 were studied. Mortality rates for leukaemia and brain tumour of highly exposed train drivers (21 muT average annual exposure) were compared with medium and low exposed occupational groups (i.e. station masters with an average exposure of 1 muT). In addition, individual cumulative exposure was calculated from on-site measurements and modelling of past exposures. RESULTS: The hazard ratio (HR) for leukaemia mortality of train drivers was 1.43 (95% CI 0.74 to 2.77) compared with station masters. For myeloid leukaemia the HR of train drivers was 4.74 (95% CI 1.04 to 21.60) and for Hodgkin's disease 3.29 (95% CI 0.69 to 15.63). Lymphoid leukaemia, non-Hodgkin's disease and brain tumour mortality were not associated with magnetic field exposure. Concordant results were obtained from analyses based on individual cumulative exposure. CONCLUSIONS: Some evidence of an exposure-response association was found for myeloid leukaemia and Hodgkin's disease, but not for other haematopoietic and lymphatic malignancies and brain tumours.

Radiation exposure to the surgeon during fluoroscopically assisted percutaneous vertebroplasty: a prospective study

STUDY DESIGN: A prospective case control study design was conducted. OBJECTIVES: The purpose of the current study was to determine the intraoperative radiation hazard to spine surgeons by occupational radiation exposure during percutaneous vertebroplasty and possible consequences with respect to radiation protection. SUMMARY OF BACKGROUND DATA: The development of minimally invasive surgery techniques has led to an increasing number of fluoroscopically guided procedures being done percutaneously such as vertebroplasty, which is the percutaneous cement augmentation of vertebral bodies. METHODS: Three months of occupational dose data for two spine surgeons was evaluated measuring the radiation doses to the thyroid gland, the upper extremities, and the eyes during vertebroplasty. RESULTS: The annual risk of developing a fatal cancer of the thyroid is 0.0025%, which means a very small to small risk. The annual morbidity (the risk of developing a cancer including nonfatal ones) is 0.025%, which already means a small to medium risk. The dose for the eye lens was about 8% of the threshold dose to develop a radiation induced cataract (150 mSv); therefore, the risk is very low but not negligible. The doses measured for the skin are 10% of the annual effective dose limit (500 mSv) recommended by the ICRP (International Commission on Radiologic Protection); therefore, the annual risk for developing a fatal skin cancer is very low. CONCLUSION: While performing percutaneous vertebroplasty, the surgeon is exposed to a significant amount of radiation. Proper surgical technique and shielding devices to decrease potentially high morbidity are mandatory. Training in radiation protection should be an integral part of the education for all surgeons using minimally invasive radiologic-guided interventional techniques.