The Ontario Workplace Health Champions Program

To increase the presence of occupational medicine in the medical school curriculum in Ontario, Canada, the Ontario Workplace Health Champions Program was established 24 years ago. The Program supports a Workplace Health Champion in each medical school who ensures there is occupational medicine content in their medical school curricula. The program has expanded to postgraduate training programs, with a focus on primary care. There has been an increase in occupational medicine content in medical schools in Ontario.

Evaluation of neurological testing for hand-arm vibration syndrome

BACKGROUND

The neurological component of hand-arm vibration syndrome (HAVS) uses the Stockholm Workshop Scale sensorineural (SWS SN) stages for classification. Proximal compressive neuropathies are common in HAVS and the symptoms are similar to SN HAVS. The SWS may not be a valid staging tool if a patient has comorbid proximal compression neuropathy.

AIMS

To evaluate the prevalence of proximal compression neuropathy in patients presenting for HAVS assessment and examine the association between compressive neuropathies and SWS SN.

METHODS

A standardized assessment protocol was used to assess 431 patients for HAVS at St. Michael's Hospital, Toronto, Ontario. The prevalence of median and ulnar compressive neuropathies was determined. The association between proximal compression neuropathies and SWS SN stage (0/1 versus 2/3) was evaluated using Chi-square and Fisher's exact tests as well as multivariable logistic regression.

RESULTS

Most patients (79%) reported numbness and 20% had reduced sensory perception (SWS SN Stage 2/3). Almost half (45%) had median neuropathy at the wrist and 7% had ulnar neuropathy. There was no association between the SWS SN stage and median or ulnar neuropathy.

CONCLUSIONS

Two neurological lesions should be investigated in patients presenting for HAVS assessment: compressive neuropathy and digital neuropathy. The prevalence of compressive neuropathies is high in patients being assessed for HAVS and therefore nerve conduction studies (NCS) should be included in HAVS assessment protocols. Comorbid proximal neuropathy does not affect the SWS SN stage; therefore, NCS and SWS SN seem to be measuring different neurological outcomes in HAVS patients.

Patient-centred care in an occupational medicine clinic

BACKGROUND

Patient-centred care (PCC) has been associated with improved patient satisfaction outcomes in a variety of clinical settings. There is a paucity of research addressing the concept of PCC in an occupational medicine context.

AIMS

To assess patient perception and compare physician and patient perceptions of patient centredness of the care at a specialty occupational medicine clinic.

METHODS

An observational study design using the Patient Perception of Patient Centeredness Questionnaire (PPPC) at an ambulatory tertiary care occupational health clinic. Results were analysed using a standardized coding system. Summary scores were compared to results reported in a primary care setting. Patient and physician scores were compared to detect physician-patient differences in perceived patient centredness of care.

RESULTS

Of 47 eligible patients 37 consented to participate and seven were excluded due to incomplete data. Summary scores of patient perceptions of patient centredness were similar but somewhat better than scores reported in a primary care setting. Perceived patient centredness of care was high and there was minimal discordance between patient and physician scores.

CONCLUSIONS

This study demonstrated that PCC can be measured in an occupational health setting. In an ambulatory tertiary care occupational health clinic there was a high degree of patient centredness of care which may be explained by a variety of factors. Future research should consider whether similar findings exist in other occupational medicine practice settings.

Functional limitations in workers with hand-arm vibration syndrome (HAVS)

Background

Hand-arm vibration syndrome (HAVS) is a chronic occupational disease affecting workers exposed to hand-transmitted vibration. However, limited information exists on task-related disability experienced by workers with HAVS.

Aims

This study was conducted to characterize the impact of HAVS on task-related disability and daily life activities.

Methods

A retrospective chart review was undertaken of difficulty in carrying out activities reported by workers with HAVS who had been assessed in an Occupational Medicine clinic in 2015. Prior to their clinical assessment, the workers had been asked to complete an open-ended questionnaire regarding activities they were having difficulty performing in the domains of personal care, household activities and recreational activities or hobbies.

Results

Data from 107 workers diagnosed with HAVS were obtained through the retrospective chart review. The activities most affected included: getting dressed (n = 72), lawn maintenance (n = 61), fishing (including ice fishing) (n = 56), snow removal (n = 36), washing the car (n = 26) and doing the dishes (n = 25).

Conclusions

These findings reported in an open-ended fashion by workers with HAVS provide a better understanding of the impact of HAVS on specific activities of daily living in comparison to highly structured questionnaires lacking any open-ended responses. Understanding the implications of HAVS on activities of daily living will contribute to the provision of patient-centred care, by enabling health care providers to effectively support HAVS patients, based on workers' actual experiences of functional limitations.

Who cares? The impact on caregivers of suspected mining-related lung cancer

Background

In the present study, we investigated the emotional, physical, financial, occupational, practical, and quality-of-life impacts on caregivers of patients with mining-related lung cancer.

Methods

This concurrent, embedded, mixed-methods study used individual in-depth qualitative interviews and the 36-item Short Form Health Survey (version 2: RAND Corporation, Santa Monica, CA, U.S.A.) quality-of-life measure with 8 caregivers of patients with suspected mining-related lung cancer who had worked in Sudbury or Elliot Lake (or both), and sometimes elsewhere. Individuals who assist workers in filing compensation claims were also interviewed in Sudbury and Elliot Lake. Interviews (n = 11) were transcribed and analyzed thematically.

Results

Caregiver themes focused on the long time to, and the shock of, diagnosis and dealing with lung cancer; not much of a life for caregivers; strong views about potential cancer causes; concerns about financial impacts; compensation experiences and long time to compensation; and suggestions for additional support. Quality-of-life scores were below the norm for most measures. Individuals who assist workers in preparing claims were passionate about challenges in the compensation journey; the requirement for more and better family support; the need to focus on compensation compared with cost control; the need for better exposure monitoring, controls, resources, and research; and job challenges, barriers, and satisfaction.

Conclusions

Caregivers expressed a need for more education about the compensation process and for greater support. Worker representatives required persistence, additional workplace monitoring and controls, additional research, and a focus on compensation compared with cost control. They also emphasized the need for more family support.

Testing the joint health and safety committee assessment tool in the education sector

Joint Health and Safety Committee (JHSC) effectiveness has been identified as an area of concern for Ontario's education sector. The JHSC Assessment Tool has been previously tested in hospitals with positive results. This study assessed the feasibility and usability of the JHSC Assessment Tool in the education sector. Members of multi-workplace JHSCs from Ontario school boards used the tool to assess their committees' effectiveness before, during and after a committee meeting with usability testing conducted pre and post meeting. Results suggested that the JHSC Assessment Tool was feasible to use during a regular JHSC meeting, groups were able to come to consensus on the majority of items, and usability scores were high overall. Participant feedback provided insight that informed the development of a version relevant to multi-workplace committees.

Using health insurance administrative data to explore patch testing utilization in Ontario, Canada-An untapped resource

BACKGROUND

Patch testing is the key diagnostic test for diagnosing allergic contact dermatitis, but there is limited information on the use of patch testing at the population level.

OBJECTIVES

To utilize Ontario Health Insurance Plan (OHIP) data to analyse trends in the rate of patch testing in Ontario.

METHODS

Patch testing billing data submitted to the OHIP between 1992 and 2014 were analysed. Two patch test billing codes were investigated: one for work-related testing (G198), and one for non-work-related testing (G206). Rates of patch testing overall were calculated, and trends over time were described.

RESULTS

There were 51 576 patch test billings: 48 416 non-work-related and 3160 work-related. The annual rate of non-work-related patch testing (G206) ranged from 11.9 per 100 000 people to 25.9 per 100 000 people, increasing over time. The rate of work-related patch testing (G198) ranged from 0.17 to 2.32 per 1 000 000 people, and was relatively stable. The overall distribution of billing by specialty was 70% dermatology, 19% other medical subspecialties, and 10% paediatrics and family medicine.

CONCLUSIONS

Administrative health data can contribute to a more complete understanding of patch test utilization at the population level and, over time, can be used to track patch testing practices.

Comparison of clinic models for patients with work-related asthma

Background

Work-related asthma (WRA) is a prevalent occupational lung disease that is associated with undesirable effects on psychological status, quality of life (QoL), workplace activity and socioeconomic status. Previous studies have also indicated that clinic structure may impact outcomes among patients with asthma.

Aims

To identify the impact of clinic structure on psychological status, QoL, workplace limitations and socioeconomic status of patients with WRA among two different tertiary clinic models.

Methods

We performed a cross-sectional analysis between two tertiary clinics: clinic 1 had a traditional referral base and clinical staffing while clinic 2 entirely comprised Worker's Compensation System referrals and included an occupational hygienist and a return-to-work coordinator. Beck Anxiety and Depression II Inventories (BAI and BDI-II), Marks' Asthma Quality of Life Questionnaire (M-AQLQ) and Work Limitation Questionnaire (WLQ) were used to assess outcomes for patients with WRA.

Results

Clinic 2 participants had a better psychological status across the four instruments compared with clinic 1 (for Beck 'Anxiety': P < 0.001 and 'Depression': P < 0.01, 'Mood' domain of M-AQLQ: NS and 'Mental Demands' domain of WLQ: P < 0.01). Clinic 2 had a greater proportion of participants with reduced income.

Conclusions

Our study indicates that clinic structure may play a role in outcomes. Future research should examine this in larger sample sizes.

Health-care barriers for workers with HAVS in Ontario, Canada

BACKGROUND

Hand-arm vibration syndrome (HAVS) becomes irreversible unless it is identified early and progression prevented.

AIMS

To describe the health-care-seeking behaviours of workers with HAVS and barriers to health care.

METHODS

We invited all patients assessed for HAVS between 15 January and 27 March 2013 at a hospital-based occupational health clinic (OHC) in Ontario, Canada, to complete a questionnaire asking why and from whom they sought health care, reasons they waited to seek care and barriers they encountered in accessing care. We analysed the data using descriptive statistics.

RESULTS

Forty-one (82%) patients agreed to participate. Thirty-seven had confirmed HAVS; 30 (84%) were Stockholm workshop vascular stage 2 or greater and 35 (97%) were sensorineural stage 1 or greater. The commonest employment sectors were construction [21 (57%)] and mining [6 (17%)]. The main reasons for seeking treatment were pain [11 (30%)], finger numbness [8 (22%)] and functional limitations [5 (14%)]. The commonest initial point of health care was the family physician [23 (66%)]. The mean wait between symptom onset and seeking treatment was 3.4 years, while the mean time between onset and OHC assessment was 9 years. Reasons for delay in seeking care were ignorance of the seriousness and irreversibility of HAVS and ability to continue to work. Family physicians suspected HAVS in 17% of cases and recommended job modification in 34%.

CONCLUSIONS

Workers with HAVS in Ontario delay seeking health care. Primary care physicians often fail to recognize HAVS. Barriers to health care include ignorance of HAVS and of the importance of prevention.

Educational intervention among farmers in a community health care setting

BACKGROUND

Farmers are at increased risk of developing work-related respiratory diseases including asthma, but little is known about their occupational health and safety (OHS) knowledge and exposure prevention practices. Educational interventions may improve knowledge and practice related to prevention.

AIMS

To determine the feasibility of an educational intervention for farmers in a community health centre setting.

METHODS

This was a pilot study. Farmers were recruited by the community health centre and completed a questionnaire on symptoms, OHS knowledge and exposure prevention practices. The intervention group received education on work-related asthma and exposure control strategies, and was offered spirometry and respirator fit testing. All subjects were asked to repeat the questionnaire 6 months later.

RESULTS

There were 68 study participants of whom 38 formed the intervention group. At baseline, almost 60% of farmers reported having received OHS training and were familiar with material safety data sheets (MSDSs); fewer (approximately 40%) reported knowledge of OHS legislation and availability of MSDSs. Approximately, two-thirds of subjects reported using respiratory protection. The response rate for repeating the questionnaire was 76% in the intervention group and 77% in the controls. Among the intervention subjects, statistically significant increases were observed in reported safety training, familiarity and availability of MSDSs and knowledge of OHS legislation.

CONCLUSIONS

Gaps in OHS knowledge were observed. The educational intervention on OHS knowledge and exposure prevention practices in the community health centre setting was feasible. Larger, more-controlled studies should be undertaken as this study suggests a positive effect on OHS knowledge and prevention practices.

Workers with occupational contact dermatitis: workplace characteristics and prevention practices

BACKGROUND

There are many gaps in knowledge related to prevention practices in place for workers who subsequently develop occupational contact dermatitis (OCD).

AIMS

To describe the workplace characteristics and the prevention practices in workplaces where workers developed hand dermatitis.

METHODS

Consecutive cases of probable OCD were enrolled from a specialist occupational health clinic. At the time of the initial assessment, questionnaires were administered to collect information about clinical presentation, workplace characteristics and prevention practices at work.

RESULTS

100 workers with hand dermatitis were enrolled in the study and 78 were considered to have OCD. Two-thirds of these had had some occupational health and safety or Workplace Hazardous Materials Information System (WHMIS) training in their workplace, however, training related to glove use and skin care was less common. Unionized workers were more likely to have received training. Workers involved in wet work were less likely to report training.

CONCLUSIONS

These findings suggest that there are gaps in prevention programs for work-related skin disease. Research is needed on effective strategies that are sustainable in the workplace.

Occupational contact allergens: are they also associated with occupational asthma?

BACKGROUND

Workplace exposures that can potentially cause both allergic occupational contact dermatitis (AOCD) and occupational asthma (OA) are not clearly identified.

METHODS

Occupational contact allergens (OCAs) were identified using North American Contact Dermatitis Group (NACDG) data. Reference documents and systematic reviews were used to determine whether each OCA had been reported to potentially cause OA. The presence or absence of a sensitizer notation in occupational hygiene reference documents was also examined.

RESULTS

The 10 most common OCAs were: epoxy resin*, thiuram, carba mix, nickel sulfate*, cobalt chloride*, potassium dichromate*, glyceryl thioglycolate, p-phenylenediamine*, formaldehyde* and glutaraldehyde*. Seven (indicated by *) were determined to be possible causes of OA. Information on sensitizing potential from OH reference materials contained conflicting information.

CONCLUSIONS

Several common OCAs can also potentially cause OA. Inhalation and dermal exposures to these agents should be controlled and both OA and AOCD should be considered as possible health outcomes. Increased consistency in sensitizer notations is needed.

Results of evaluating health care workers with prick and patch testing

BACKGROUND

Health care workers are exposed to many agents that can cause irritant or allergic contact dermatitis. Recently, much attention has been focused on latex sensitivity, which commonly causes contact urticaria. Most studies have examined the conditions of irritant or allergic contact dermatitis and contact urticaria independently. Therefore, we have little information about the possible occurrence of these conditions in the context of combined assessment including both prick and patch testing.

OBJECTIVE

To determine the prevalence of irritant and allergic contact dermatitis and contact urticaria in a group of health care workers presenting with skin problems.

METHODS

Retrospective review of health care workers assessed by both prick and patch testing in an occupational health clinic.

RESULTS

The diagnoses included 61% with irritant contact dermatitis, 31% with allergic contact dermatitis, and 27% with contact urticaria to latex. Eleven percent had both allergic contact dermatitis related to thiuram and contact urticaria to latex. Ninety five percent were deemed to be work-related.

CONCLUSION

Health care workers presenting with skin complaints should be assessed with both prick and patch testing.

Dermatitis in a particleboard manufacturing facility

Exposure to wood dust and other chemicals used in particleboard manufacture may cause contact dermatitis. To assess the prevalence and nature of skin complaints in the refining and drying department of a particleboard manufacturing facility following introduction of a new process, workers were assessed by a physician, using a standardized questionnaire concerning symptoms, past and family history, workplace exposures, and use of protective equipment. Cutaneous examination and patch testing were then performed. Questionnaire results showed that workers complained of rash, nasal and eye irritation, as well as cough and bothersome odours. Cutaneous examination identified a heterogeneity of skin problems, with dermatitis being mainly irritant rather than allergic. Quaternium-15 (Dowicil 200) was the only allergen to which more than 1 individual reacted. Aside from the odours, exposure to wood dust could account for the other reported symptoms. Allergic reactions on patch testing were few and did not explain the dermatitis; most skin reactions were irritant. Recommendations to the company included improved dust control, through ventilation and personal hygiene measures, as well as protective clothing. The investigation highlights how the introduction of a new process may focus attention on health complaints that have been present for some time before.

Results of a quality of life questionnaire in a patch test clinic population

There has been increasing interest in quality of life outcomes, but there has been little reported on this topic for individuals with contact dermatitis. The objectives of this study were (i) to pilot a dermatology-specific quality of life instrument to assess its acceptability in a patch test clinic population, (ii) to see the effects of contact dermatitis on the patients' lives and (iii) to determine what factors may influence quality of life outcomes in this population. A dermatology-specific quality of life instrument was modified and used for 339 patients undergoing patch testing in a contact dermatitis clinic. The most common effect was pain or itching in 61%. Approximately 1/3 noted embarrassment, interference with work, or sleep disturbance. Other concerns were reported by less than 25% of the population. On multivariate analysis, the key factor influencing most outcomes was hand involvement. The instrument was well accepted by the clinic population and is now being used in a prospective study of outcomes. In the population assessed, it demonstrated the effects of disease. Analysis suggests that a key factor influencing these quality of life outcomes is hand involvement.

Asthmatic subjects symptomatically worse at work: prevalence and characterization among a general asthma clinic population

STUDY OBJECTIVES

To assess the prevalence of a historical occupational component to asthma in an adult asthma clinic and to compare characteristics of asthmatic subjects with and without work-attributed symptoms.

DESIGN

A retrospective review of data obtained from a physician-administered questionnaire, answers to which were obtained at the initial patient visit of asthmatic subjects, and which included specific questions regarding the relationship of work to symptoms. Chart review data were used to supplement information on workplace exposures and investigations.

SETTING

A university-based secondary- and tertiary-referral asthma clinic.

PATIENTS

Seven hundred thirty-one adult asthmatic subjects who were referred for assessment and management of asthma.

INTERVENTIONS

Statistical analyses of asthmatic subjects with and without work-attributed symptoms and a determination, from chart review, of the likelihood of causes for symptomatic worsening of asthma at work.

MEASUREMENTS AND RESULTS

Sixty percent of the patients (435) had adult onset of asthma, among whom 310 patients (71%) were employed at the time of their visit. Fifty-one patients reported their asthma to be worse at work (ie, 16% of adult-onset working asthmatic subjects). Sixteen of these patients (31%) had likely or possible sensitizer-induced occupational asthma (OA), and 49% likely had aggravation of underlying asthma. The other 20% of patients had possible OA or aggravation of underlying asthma at work.

CONCLUSIONS

Adult-onset asthmatic subjects commonly report a worsening of asthma at work, more commonly on the basis of likely aggravation of underlying asthma than on the basis of likely or possible OA.

Expanding the epidemiologic profile: risk factors for active tuberculosis in people immigrating to Ontario

BACKGROUND

Many people immigrating to Canada come from countries with a high burden of tuberculosis. The aim of this study was to develop a detailed epidemiologic profile of foreign-born people with tuberculosis living in Ontario.

METHODS

In this population-based case-control study, cases of tuberculosis diagnosed in 1994-1995 were identified from the database of the Ontario Reportable Disease Information Service and were considered eligible for analysis if a record of landing (receipt of permission to establish residence in Canada) from the period 1986-1995 was found in the Citizenship and Immigration Canada (CIC) database, if the person was at least 11 years of age at the time their visa was issued, and if the person had not been diagnosed with tuberculosis before becoming legally landed in Canada. Control subjects, who met the same criteria as the case subjects but who did not have tuberculosis in 1994-1995, were identified from a CIC database for landed immigrants.

RESULTS

A total of 1341 cases of tuberculosis in foreign-born people were reported in Ontario in 1994-1995. A record of landing was found in CIC databases for 1099 of these people, 224 of whom were not legally landed at the time of diagnosis. In total, 602 cases met the inclusion criteria. The 2 strongest determinants of risk among those who had become landed within the preceding 10 years were referral for medical surveillance by immigration officials (odds ratio [OR] 3.8, 95% confidence interval [CI] 2.6-6.0) and world region of origin (Somalia [OR 67.7, 95% CI 31.3-154.9], Vietnam [OR 25.0, 95% CI 12.5-50.0], the Philippines [OR 11.9, 95% CI 6.0-23.3], other sub-Saharan African countries [OR 11.6, 95% CI 5.7-23.2], India [OR 9.7, 95% CI 4.9-18.9], China [OR 6.1, 95% CI 3.1-12.1], other Asian countries [OR 4.7, 95% CI 2.4-9.1], the Middle East [OR 4.1, 95% CI 2.0-8.3], Latin America [OR 1.9, 95% CI 0.9-3.8), and the former socialist countries of Europe [OR 1.8, 95% CI 0.8-3.8]; the reference category was countries with established market economies). Low socioeconomic status was an independent risk factor.

INTERPRETATION

The risk of tuberculosis in groups of people migrating to Ontario is highly variable and is influenced by several factors. Successful population-based tuberculosis prevention strategies will need to accommodate this variability.

Results of a pilot study reviewing dermatitis claims submitted to the Ontario Workplace Safety and Insurance Board

BACKGROUND

Workers who develop occupational skin disease are often eligible for workers' compensation benefits; however, there is little known about the decision-making process for adjudicating claims submitted for work-related skin problems.

OBJECTIVE

The objective of this pilot study was to test a file abstraction instrument and determine the nature of information that was available for decision-making.

METHODS

Files submitted to the Ontario Workplace Safety and Insurance Board (WSIB) in 1995 for dermatitis were identified. The last 51 files were abstracted to collect information concerning demographics, physicians seen, information available in the claim file for decision making, as well as type of claim and outcome of the claim.

RESULTS

Approximately 70% of the claims were "no-lost-time" and one-third of total claims were accepted for compensation. Although there was reasonable information related to the clinical status, most claims had no information that related to workplace issues such as exposures or association with work. Claims that were for lost time or were accepted had more information available.

CONCLUSIONS

The pilot study has demonstrated that there is a lack of information related to workplace issues that would be important in decision-making. The study will be extended to examine the entire year's claims in order to develop a strategy to enhance the understanding of the WSIB and providers regarding the information necessary for decision-making and to determine methods to facilitate its collection.

Occupational health and safety management systems in the Canadian pulp and paper industry: methods of auditing

The Canadian Pulp and Paper Association has developed eight "Guiding Principles for Management of Occupational Health and Safety" (OH&S) for its member companies. As part of a study to assess member companies' OH&S activities, an on-site audit was performed for 11 sites. The audit assessed five key components of a management system for a number of OH&S activities. Management-system components more likely to be in place included system ownership and goals and procedures, whereas measures of performance, a review of measures, and corrective action were less likely to be present. Environmental surveillance and injury reduction were most actively monitored, as indicated by the number of measures of performance relating to these activities. The auditing process demonstrated leadership and communicated the OH&S priorities of the Canadian Pulp and Paper Association to the sites.

Prevalence of upper extremity symptoms and possible risk factors in workers handling paper currency

The prevalence of upper extremity symptoms in the workforce is high, particularly in industries characterized by forceful, repetitive or awkward movements. A study was undertaken to assess the prevalence of upper extremity symptoms in bank workers in a paper currency processing operation and to examine the role of possible risk factors for these complaints. Thirty-nine workers of a total workforce of 47 were assessed with a questionnaire and physical examination. The questionnaire collected information about demographics, health status, symptom reporting, psychosocial work stressors and other work exposure characteristics. Overall, 59% of the workers reported having significant work-related upper extremity musculoskeletal symptoms in the preceding year, including 49% with neck and shoulder symptoms and 49% with arm and wrist symptoms. In this study the key predictive factor for upper extremity musculoskeletal symptoms was psychological job demands. The workers had similar ergonomic stressors (with little gradient of exposure) and therefore our results do not contradict the importance of ergonomic factors in the development of upper extremity symptoms. However, the results do suggest that within a group exposed to similar ergonomic stressors, psychological job demands may be an important factor associated with musculoskeletal symptoms.

Incidence of latex sensitization among latex glove users

BACKGROUND

Although there are several reports of the prevalence of latex sensitization among health care workers, the incidence of sensitization is unknown.

OBJECTIVE

The objective of this study was to estimate the incidence of sensitization among latex glove users at a hospital in Hamilton, Ontario, Canada.

METHODS

Workers with negative results to the skin test at baseline were followed prospectively over 1 year, some wearing powdered gloves and others using powder-free gloves. They were reevaluated in 1995 with a questionnaire and skin prick test (SPT) sensitivity to latex reagents, three common inhalants, and six foods. A conversion was defined as a (new) latex SPT with wheal diameter at least 4 mm greater than saline control. Glove extracts were assayed for antigenic protein, and air samples were obtained to estimate exposure to airborne latex protein.

RESULTS

During powdered glove use, personal exposures ranged from 5 to 616 ng/m3, whereas during powder-free glove use, all but two results for air samples were below the limit of detection (about 0.1 ng/m3). During the study period, the protein concentration in the powdered gloves, initially mean 557 microg/gm of sample, declined at a rate of 295 microg/gm per year (p < 0.0001). Of the 1075 SPT-negative participants at baseline, 479 were working in eligible wards, and of these, 435 (91%) participated in follow-up, 227 using powder-free gloves and 208 using powdered gloves. We identified four conversions, two (1.0%) in the powdered glove group and two (0.9%) in the powder-free group. The two participants using powdered gloves were the only converters who were symptomatic. The significance of skin test conversions identified in the powder-free group, both asymptomatic patients, is unclear. The limitations of the study are discussed, including the limited power, the declines in latex protein concentrations, and the possibility of information (observer) bias.

CONCLUSION

To our knowledge, this represents the first reported estimate (about 1%) of incidence of sensitization in hospital personnel using latex gloves.

Characteristics of occupational medicine practitioners and practice in Canada

To obtain baseline information with respect to occupational medicine practice in Canada, a questionnaire survey of members of the Occupational and Environmental Medical Association of Canada was carried out by mail in 1993. One hundred eighty-six responses were received (56% of the membership). The average age of the respondents was 49.5, 12% were female, and 55% worked full-time in occupational medicine. Practice types included corporate settings (58%), clinics (23%), government agencies (14%), worker's compensation boards (7%) and academic settings (5%). Sixty percent had some formal training in occupational medicine, and 46% had occupational medicine certification by either the Royal College of Physicians and Surgeons of Canada, the Canadian Board of Occupational Medicine, or the American Board of Preventive Medicine. Younger physicians were more likely to be female and have gone directly into occupational medicine. Women were more likely to be working full-time in occupational medicine but worked fewer hours per week. Those physicians with specialty qualifications were older and more likely to be working full-time in occupational medicine and be active in professional activities. The Association intends to continue surveying its members on a triennial basis, identifying trends in the practice profiles and continuing education needs.

Investigation of factors affecting mass psychogenic illness in employees in a fish-packing plant

This study of the factors affecting the development of mass psychogenic illness (MPI) was carried out in a large fish-packing plant in New Brunswick, Canada. A total of 269 out of 270 plant employees (99.6%) participated in the study and of these, 208 cases were affected with symptoms of MPI and 61 controls were unaffected over a period of 2 1/2 months. A questionnaire was administered to participating employees to collect information about symptoms, demographic factors, work history, pre-existing medical problems, potential workplace triggering exposure factors, and various psychosocial factors. Multiple logistic regression indicated that the main factors associated with MPI, in decreasing order of importance, were skill creation in the job, odor perception, and female sex. Management of this incident required reassurance of employees that there was no hazardous exposure in the plant as well as recognition of the need to reduce underlying sources of stress in the work environment.

Results of patch testing with a specialized collection of plastic and glue allergens

Patch testing was performed on 235 patients with a specialized collection of plastic and glue components. Thirteen percent had a positive response to at least one of the allergens. Seventy-four percent of the responses were relevant to either the present or a past problem, and 64% were occupationally related. The substances that yielded the greater percentage of positive responses were ethylenediamine, triethylenetetramine, diethylenetriamine, diaminodiphenylmethane, melamine formaldehyde resin, phenol formaldehyde resin, cresylglycidylether, phenylglycidylether, and N, N-dimethyl-p-toluidine. Of the 47 agents used, 26 did not elicit any positive responses. There were few distinguishing characteristics between those who exhibited a positive response to these agents and those who did not. In 12 cases (5% of those tested), the diagnosis of allergic contact dermatitis would have been missed if the plastics and glues components were not used.

Latex allergy: epidemiological study of 1351 hospital workers

OBJECTIVE

To determine the prevalence of latex sensitisation among a large group of healthcare workers, study the occupational and non-occupational factors associated with latex allergy, and characterise latex exposure in air and by gloves.

METHODS

All 2062 employees of a general hospital in Hamilton, Ontario, Canada who regularly used latex gloves were invited to participate in a cross sectional survey, representing the baseline phase of a prospective cohort morbidity study. Attempts were made to recruit employees who were diagnosed with latex allergy before the survey. Glove extracts were assayed for antigenic protein, and area and personal air samples were obtained on two occasions (summer and winter) to estimate exposure to airborne latex protein. A questionnaire on medical and occupational information was administered by an interviewer. Skin prick tests were performed with latex reagents, three common inhalants, and six foods.

RESULTS

The mean (SD) latex protein concentrations were 324 (227) micrograms/g in powdered surgical gloves and 198 (104) micrograms/g in powdered examination gloves. Personal latex aeroallergen concentrations ranged from 5 to 616 ng/m3. There was a total of 1351 (66%) participants. The prevalence of positive latex skin tests was 12.1% (95% confidence interval (95% CI) 10.3% to 13.9%). This prevalence did not vary by sex, age, hospital, or smoking status but subjects who were latex positive were significantly more likely to be atopic (P < 0.01). Participants who were latex positive were also significantly more likely to have positive skin tests to one or more foods (Mantel-Haenszel odds ratio (OR) adjusted for atopy 12.1, 95% CI 7.6 to 19.6, P < 10(-9)). Work related symptoms were more often reported among latex positive people, and included hives (OR 6.3, 95% CI 3.2 to 12.5), eye symptoms (OR 1.9, 95% CI 1.2 to 2.8), and wheezy or whistling chest (OR 4.7, 95% CI 2.8 to 7.9). The prevalence of latex sensitivity was highest among laboratory workers (16.9%), and nurses and physicians (13.3%). When the glove consumption per healthcare worker for each department was grouped into tertiles, the prevalence of latex skin test positivity was greater in the higher tertiles of glove use for sterile (surgical) gloves (P < 0.005) but not for examination gloves.

CONCLUSIONS

In this large, cross sectional study of healthcare workers, the prevalence of latex sensitisation was 12.1% (9.5% among all those eligible), and there were significant associations with atopy, positive skin tests to certain foods, work related symptoms, and departmental use of gloves per healthcare worker. This cohort is being followed up prospectively and will be retested to determine the incidence of development of latex sensitivity.

Results of patch testing with a special series of rubber allergens

The purpose of this study was to examine the results of patch testing with the rubber components on a standard screening tray and compare them with the results of testing with a special series of 27 rubber components (rubber tray). 1670 patients were patch tested with the screening tray and 317 of these were also tested with the rubber tray. 16% of those tested with the rubber tray had a positive response to at least 1 of the rubber allergens on the screening tray and 22% had a positive response to at least 1 of the allergens on the rubber tray. The most common positive response to the rubber tray allergens was to tetramethylthiuram monosulfide. There were no responses to 3 of the components on the rubber tray and there was only 1 positive response to a further 4 components. The diagnostic test characteristics of the rubber components on the screening tray were examined using the rubber tray as the gold standard. The sensitivity of the screening tray was 94%, specificity 51%, positive predictive value 87% and negative predictive value 71%. Of the 317 tested, 11% were found to have a positive to a substance on the rubber tray that was not evident from the results of the screening tray.

Latex sensitivity in dental students and staff: a cross-sectional study

BACKGROUND

Dental practitioners, like other health care providers who regularly use latex gloves, are at increased risk for latex sensitivity. They are also at risk for irritant or allergic contact dermatitis.

OBJECTIVE

This study was carried out to determine the prevalence of latex sensitivity and possible risk factors in staff and students of a Faculty of Dentistry.

METHODS

A cross-sectional study was performed by using a questionnaire and allergy skin prick testing.

RESULTS

Two hundred three students and staff members completed the questionnaire. Five percent reported asthma symptoms on exposure to rubber products, 13% reported symptoms of rhinitis or conjunctivitis, and 17% reported pruritus or urticaria within minutes of exposure to rubber. Overall, 10% of 131 subjects who underwent skin prick tests had a positive response to natural rubber latex. Among the students tested, there were increasing percentages of positive skin test responses to latex with increasing years of study (0% of Year 1 and 2 students tested; 6% of Year 3; and 10% of Year 4). Positive responses were seen as early as Year 3 in students (in their second year of clinical activity and glove use). Positive skin prick test responses to latex were related to a personal history of atopy (p = 0.005), positive prick test responses to common allergens (p < 0.005), latex-attributed immediate pruritus or urticaria (p < 0.05), rhinoconjunctivitis (p < 0.001), and asthma symptoms (p < 0.001).

CONCLUSION

Dental school students and faculty are at high risk for latex sensitization. This occurs as early as the second year of glove use. Overall prevalence of skin sensitization was 10% of those tested. Preventive strategies in this group merit further investigation.

Medications as risk factors for farm injury

A case-control study was used to determine whether cases of farm injury were more likely than controls to have been regularly exposed to certain types of medication including those that cause side effects which may predispose to injury. Persons reporting an injury (n = 176) were identified in a population-based mail survey of people on 1364 Ontario farms, and compared to people without injuries using a 4:1 control: case ratio. Bivariate, stratified, and multivariable analyses were used to quantify the strength of associations between exposures to certain medications and the occurrence of farm injury. Those who regularly used certain types of medication were separated into two groups: people who used the medications in isolation, and those who used the medications in combination with other medications. Response to the survey was 77.3% among cases and 82.6% among controls. Strong and statistically significant increases in risk for injury were observed in association with the regular use of stomach remedies or laxatives by males (OR 2.8; 95% CI: 1.0,7.7), and regular use of heart of circulatory medications by men over the age of 45 (OR 4.2; 95% CI: 1.2,14.7). The identified associations remained after adjustment for age, co-morbidity, tillable farm acreage, education, income, alcohol consumption and tobacco use. Several possible explanations for the occurrence of the identified associations, other than the etiological hypothesis originally advanced, are discussed.

Work outcome in workers with occupational skin disease

We carried out a follow-up study of employment outcome for 230 workers with a diagnosis of occupational skin disease who were at least 2 years postdiagnosis. Seventy-eight percent of the workers were working, but 57% of those working had changed jobs, 67% because of their skin problem. Thirty-one percent had lost no time from work because of their skin disease, while 35% had lost at least 1 month. Forty-three percent had applied for workers' compensation benefits, and 87% of those who had applied were successful in their claims. Older workers were more likely to be unemployed and to have applied for workers' compensation benefits. Women were less likely to have lost time from work and to have applied for workers' compensation. Those who had changed their jobs tended to have a better outcome with respect to active dermatitis, though they had lost more time from work and had more often applied for workers' compensation benefits.

Exposure characteristics and cutaneous problems in operating room staff

Health care personnel have exposure to a variety of cutaneous irritants and allergens and a high prevalence of cutaneous problems. The objectives of this exploratory study were to characterize the exposures and determine the prevalence of cutaneous symptoms and findings in operating room personnel, and to examine relationships between exposure characteristics and cutaneous outcomes. A questionnaire and standardized hand examination were used to assess the exposures and cutaneous status of operating room personnel. 184 operating room staff (90% of the eligible population) were assessed. Current skin problems were reported by 26%. Hand examination revealed that 9% had findings consistent with eczema and 10% changes of moderate dryness. A variety of preventive practices were being used by those with symptoms or findings. Cutaneous problems are common in operating room personnel. The use of preventive strategies (changing the type of gloves worn or the type of soap used for scrubbing, the use of glove liners and emollients) varied between different groups. These workers might benefit from more education regarding cutaneous hazards, preventive stategies and the importance of appropriate investigation of these problems.

Concomitant positive patch test results with standard screening tray in North America 1985-1989

Responses to patch test substances may occur contemporaneously. Such simultaneous reactions may reflect concomitant sensitization to 2 dissimilar allergens to which concurrent exposure has taken place (e.g., ethylenediamine dihydrochloride and neomycin). It may occur when the individual has been exposed to only 1 of the substances and exhibits a response to other substances of similar chemical structure (i.e., cross-sensitization such as between para-phenylenediamine and benzocaine). Such simultaneous responses may also be chance occurrences, reflecting multiple sensitization or the result of altered response due to the "angry back syndrome". This investigation established that such concurrence of response is not uncommon and adds further documentation to the literature of these associations in patch test responses.

Disease outcome in workers with occupational skin disease

BACKGROUND

Occupational contact dermatitis (OCD) contributes significantly to the burden of occupational disease, but there is little known about prognostic factors.

OBJECTIVE

The study was designed to determine the health status of workers with OCD at least 2 years after diagnosis and to identify risk factors related to prognosis.

METHODS

A questionnaire study was conducted of workers with a diagnosis of work-related skin disease.

RESULTS

Of the 201 workers with OCD, 76% noted improvement and 40% reported that they were currently free of any eruption. Approximately one third noted that their skin disease interfered with household, work, or recreational activities. The key prognostic factor appeared to be sex because women reported a better outcome. Diagnosis and atopic status tended to be related to some outcomes, whereas age was not.

CONCLUSION

Examination of other possible factors, some of which may be associated with sex, that might affect outcome should be undertaken to gain a better understanding of possible management strategies. A retrospective study has methodologic limitations and a prospective intervention trial should yield more information.

Characteristic features of occupational dermatitis: epidemiologic studies of occupational skin disease reported by contact dermatitis clinics

Numerous issues concerning occupational dermatitis are covered, including age and gender of workers it affects, its anatomic location, and length of time a single eruption lasts. Extensive tables show the results of patch testing in various populations.

The performance of specialized collections of bisphenol A epoxy resin system components in the evaluation of workers in an occupational health clinic population

Epoxy resin of the bisphenol A type (ERBA) is a common cause of occupational contact dermatitis. 167 patients with a history of potential exposure were patch tested with epoxy resin (molecular weight 340) (ERBAM) 1% in pet. and with a number of other ingredients in ERBA systems. 18% of the test patients exhibited a positive response to ERBAM. Phenyl glycidyl ether was the most frequent system component other than ERBAM itself to elicit a positive response (6.1%). Approximately 80% of those tested were unresponsive to ERBAM or any other of the system components, while 20% exhibited a positive response to one or more of the test materials. Only a small % were positive to system materials, but negative to ERBAM, in keeping with previous studies. The study suggests that there is a marginal benefit to testing with other than ERBAM 1%, except in instances where there is known exposure to another ERBA system ingredient, in which event, the patient should also be tested with the specific material to which they have been exposed if there is no response to ERBAM.

Hypersensitivity pneumonitis and airways hyperreactivity induced by occupational exposure to penicillin

A patient with penicillin-induced hyperreactive airways in association with hypersensitivity pneumonitis is described. Patch tests and intradermal tests to penicillin were positive. Bronchoalveolar lavage demonstrated a relative lymphocytosis and mild neutrophilia. Symptoms and physiologic abnormalities of pulmonary function and gas exchange resolved on cessation of exposure to penicillin.

Scabies in chronic health care institutions

BACKGROUND

The diagnosis and management of outbreaks of scabies in health care facilities may be difficult. As there is little information available regarding the extent of this problem we conducted a questionnaire study to provide an indication of the occurrence of scabies in chronic health care facilities in the province of Ontario, Canada. It also documented the facilities' approach to the management of the disease.

OBSERVATIONS

Two outbreaks of scabies in chronic health care facilities are described. The questionnaire study revealed that 25% of the institutions reported that they had problems with scabies over a 1-year period. A minority had a written policy with respect to dealing with the management of scabies, particularly in the setting of a mass outbreak.

CONCLUSIONS

Scabies is a common problem in chronic health care facilities; however, diagnosis and management may be difficult. The development of a specific protocol for the management of such outbreaks by the appropriate public health agencies would be useful.

Health effects of Halon 1301 exposure

An accidental discharge of a Halon 1301 system is reported. Thirty-one workers were assessed, 22 who were present at the time of the discharge, and 9 who worked the next shift. The incident was complicated by a small Freon-22 leak several hours later. Throat, eye, and nasal irritation and lightheadedness were reported by the majority of workers. Workers present during the halon discharge reported significantly more lightheadedness, headache, voice change, cough, and a fast heartbeat than did those who worked the later shift. These differences were significant even after correcting for confounding factors such as age, sex, and sense of anxiety at the time of the incident. The possible causes for the irritant symptoms include breakdown products of Halon 1301 and Freon-22 or contaminants from the halon discharge system. Although these irritant effects may not be an effect of Halon 1301 alone, they may occur in these discharge situations, and workers should be advised of this possibility. The possible cardiac and central nervous system effects also should be considered. The importance of a clear-cut protocol to deal with such incidents as well as worker education are discussed.

Work-related toxic epidermal necrolysis?

A case of toxic epidermal necrolysis is described in an employee of a company that carries out plastic extrusion using various resins, including cellulose acetate, co-polyester, polyvinyl chloride, acrylonitrile-butadienestyrene, and polyethylene. Air sampling during normal operating conditions indicated only trace amounts of hydrogen chloride and the plasticizer diethylphthalate. However, pyrolysis products of resin plugs could include compounds such as formaldehyde, acrylonitrile, and chlorinated hydrocarbons that have been associated with previous case reports of either erythema multiforme, Stevens-Johnson syndrome, or toxic epidermal necrolysis. The development of toxic epidermal necrolysis in this worker was directly preceded by exposure to a vapor from a machine used to dry cellulose acetate. The problems in determining work relatedness and advising about return to work are discussed.

Medical management of three workers following a radiation exposure incident

The medical management of three individuals involved in an exposure incident to whole-body radiation at a nuclear generating plant of a Canadian electrical utility is described. The exposure incident resulted in the two highest whole-body radiation doses ever received in a single event by workers in a Canadian nuclear power plant. The individual whole-body doses (127.4 mSv, 92.0 mSv, 22.4 mSv) were below the threshold for acute radiation sickness but the exposures still presented medical management problems related to assessment and counseling. Serial blood counting and lymphocyte cytogenetic analysis to corroborate the physical dosimetry were performed. All three employees experienced somatic symptoms due to stress and one employee developed post-traumatic stress disorder. This incident indicates that there is a need in such radiation exposure accidents for early and continued counseling of exposed employees to minimize the risk of development of stress-related symptoms.

Is a worker's understanding of their diagnosis an important determinant of outcome in occupational contact dermatitis?

The possible effect of an individual's knowledge of their diagnosis on their disease outcome was examined in a group of 230 workers with occupational contact dermatitis. The workers were surveyed with an interviewer-administered questionnaire for an average of 5 years following a diagnosis of occupational contact dermatitis. 48% had allergic contact dermatitis and 52% had irritant contact dermatitis. There was a poor correlation between the workers' recalled diagnosis and the actual diagnosis, but better concordance with their recollection of patch test results. Only 33% correctly identified their diagnosis. Those who could not were approximately 2 x as likely to still have active dermatitis, to have more severe dermatitis and to note that their skin problem interfered with their work and home activities. Those who had no idea of their diagnosis were 3 x as likely to have these problems. These results raise the possibility that further efforts directed at the patient's education with respect to their condition might improve the outcome of their occupational skin disease.

Cutaneous nickel sensitivity in Toronto, Canada

Patch tests were administered to 1074 subjects with suspected contact dermatitis by the method recommended by the International Contact Dermatitis Research Group. Of 629 subjects tested with 5% nickel sulfate in petrolatum, 10.5% had positive reactions (males, 5.1%; females, 16.7%). Of 447 subjects tested with 2.5% nickel sulfate in petrolatum, 11.9% reacted (males, 7.7%; females, 16.9%). In 447 subjects in whom the relationship between clinical findings and the patch test response was evaluated (i.e., relevance), more than 90% of the responses could be related to a past or present problem with contact dermatitis. The sites of involvement were not different between nickel-sensitive subjects and the overall population tested, except in the case of foot involvement, which was underrepresented in the nickel-sensitive group. Patients who had positive responses to nickel reacted more frequently to marginal irritants such as formaldehyde and benzoyl peroxide. This finding may suggest a reduction in the irritancy threshold in nickel-sensitive subjects. In most instances, domestic rather than occupational exposure was thought to account for the induction of nickel allergy.