Incidence of occupational asthma by occupation and industry in Finland

Airway Symptoms among Farmers in Central Norway. A Comparative Study of Risks. The HUNT Study

OBJECTIVES

The objective of this study was to compare the risk of developing respiratory symptoms in farmers and other occupational groups over a period of 11 to 23 years.

METHODS

The study includes data from questionnaires and interviews in HUNT1-3 in The Trøndelag Health study (HUNT). In all three surveys, farmers can be identified. Two control groups are used. Control group 1 consists of all HUNT participants who are not farmers or fishermen. Control group 2 consists of occupational groups who presumably have low exposure to dust, chemicals or gases, but similar educational status as farmers. The data are analysed in SPSS 25 (IBM, Armonk NY), with use of frequency analyses and multiple binary logistic regressions.

RESULTS

Our main finding is that healthy farmers have increased risk of developing respiratory symptoms as wheezing or breathlessness over a period of 11 and 23 years. This increased risk is statistically significant after 11 years of follow-up (HUNT1 to HUNT2), and also after 23 years (HUNT1 to HUNT3). Corresponding results regarding wheezing and breathlessness are found for healthy farmers in HUNT2 after 12 years of follow-up in HUNT3. In a subgroup analysis, we find a highly significant difference in both wheezing and shortness of breath when at work, in believing that the symptoms are caused by work, and in having to change jobs or quit because of breathing problems.

CONCLUSION

Farmers have more respiratory symptoms than controls, and the main symptom is attacks of wheezing or breathlessness. Preventive measures such as ventilation and respiratory protection should be implemented on the farm.

Occupational Disease in New York State: An Update

An assessment of occupational disease in New York State was undertaken that partially replicated and expanded earlier work from 1987. Utilizing an expanded conception of occupational disease, the assessment used a variety of data sources and methods to provide estimates of mortality and morbidity of occupational disease; workers exposed to specific workplace hazards; disparities in occupational disease among racial/ethnic groups and gender; costs and distribution of costs of occupational disease; and accessible occupational medical resources. Examples of the pathways work may impact health in some of the major health issues of current import including stress-related health conditions; substance use; and overweight/obesity were included. The report contains recommendations for addressing the problem of occupational disease in New York State and advocates for the convening of a statewide group to develop an occupational disease prevention agenda.

Occupational Health and Safety Statistics as an Indicator of Worker Physical Health in South African Industry

Operations in general industry, including manufacturing, expose employees to a myriad of occupational health hazards. To prevent exposure, occupational health and safety regulations were enacted, with both employers and workers instituting various risk reduction measures. The analysis of available occupational disease and injury statistics (indicators of worker physical health) can be used to infer the effectiveness of risk reduction measures and regulations in preventing exposure. Thus, using the READ approach, analyses of occupational disease and injury statistics from South African industry, derived from annual reports of the Compensation Fund, were conducted. The publicly available database of occupational disease and injury statistics from the South African general industry is unstructured, and the data are inconsistently reported. This data scarcity, symptomatic of an absence of a functional occupational disease surveillance system, complicates judgement making regarding the effectiveness of implemented risk reduction measures, enacted occupational health and safety regulations and the status of worker physical health from exposure to workplace hazards. The statistics, where available, indicate that workers continue to be exposed to occupational health impacts within general industry, notwithstanding risk reduction measures and enacted regulations. In particular, worker physical health continues to be impacted by occupational injuries and noise-induced hearing loss. This is suggestive of shortcomings and inefficiencies in industry-implemented preventive measures and the regulatory state. A robust national occupational disease surveillance system is a regulatory tool that should detect and direct policy responses to identified occupational health hazards.

Occupations and exposure events in acute and subacute irritant-induced asthma

Background

Exposures leading to irritant-induced asthma (IIA) are poorly documented.

Methods

We retrospectively screened the medical records of patients with IIA diagnosed in an occupational medicine clinic during 2000–2018. We classified the cases into acute (onset after single exposure) and subacute (onset after multiple exposures) IIA. We analysed in detail, occupations, causative agents and their air levels in the workplace, exposure events and the root causes of high exposure.

Results

Altogether 69 patients were diagnosed with IIA, 30 with acute and 39 with subacute IIA. The most common occupational groups were industrial operators (n=23, 33%), metal and machinery workers (n=16, 11%) and construction workers (n=12, 8%). Among industrial operators significantly more cases had subacute IIA than acute IIA (p=0.002). Forty cases (57%) were attributable to some type of corrosive acidic or alkaline chemical. Acute IIA followed accidents at work in different types of occupation, while subacute IIA was typical among industrial operators performing their normal work tasks under poor work hygiene conditions. The most common root cause was lack of information or false guidance in acute IIA (n=11, 36%) and neglect of workplace hygiene measures in subacute IIA (n=29, 74%).

Conclusions

Accidents are the main causes of acute IIA, whereas subacute IIA can develop in normal work in risk trades with poor work hygiene. Airborne strong acids or bases seem to be the most important causative agents of acute and subacute IIA. The different risk profiles of acute and subacute IIA should be considered in the prevention and identification of the cases.

Unusual allergen in a butcher with respiratory symptoms

A 37-year-old butcher developed respiratory symptoms during sausage and chicken production in a large company. In addition to various spices, the enzyme transglutaminase was a possible cause. The lung function test showed mild partial reversible airway obstruction and severe bronchial hyperresponsiveness. The IgE test showed sensitizations to various spice mixtures, coriander (0.74 kU/L), and to the ImmunoCAP-bound transglutaminase preparation from the workplace (7.12 kU/L). The skin prick tests with this transglutaminase were also positive. In the immunoblot of this preparation, a 40-kD protein reacted with the patient’s IgE and was identified as transglutaminase from Streptomyces mobaraensis by inhibition experiments. This is the first case of a butcher with an allergy to transglutaminase. After moving to a small enterprise without enzyme use, his symptoms improved. Sensitization and the course of the symptoms indicate a dominant role of transglutaminase in the patient’s allergic asthma.

Work-related asthma: A position paper from the Thoracic Society of Australia and New Zealand and the National Asthma Council Australia

Work-related asthma (WRA) is one of the most common occupational respiratory conditions, and includes asthma specifically caused by occupational exposures (OA) and asthma that is worsened by conditions at work (WEA). WRA should be considered in all adults with asthma, but especially those with new-onset or difficult to control asthma. Improvement in asthma symptoms when away from work is suggestive of WRA. Clinical history alone is insufficient to diagnose WRA; therefore, objective investigations are required to confirm the presence of asthma and the association of asthma with work activities. Management of WRA requires pharmacotherapy similar to that of non-WRA, however, also needs to take into account control of the causative workplace exposure. Ongoing exposure will likely lead to decline in lung function and worsening asthma control. WRA is a preventable condition but this does rely on increased awareness of WRA and thorough identification and control of all potential occupational respiratory hazards.

Assessment of Respiratory Problems in Workers Associated with Intensive Poultry Facilities in Pakistan

Background

The poultry industry in Pakistan has flourished since the 1960s; however, there are scarce data regarding the impact of occupational exposure on the pulmonary health of farm workers in terms of years working in the industry. The objective of the present study was to assess the effect of poultry environment on the health of occupationally exposed poultry farmers in countries of warm climatic regions, such as Pakistan. This study will also show the effect of exposure to poultry facilities on the health of poultry farmers in the context of low-income countries with a relatively inadequate occupational exposure risk management.

Materials and methods

The lung function capacity of 79 poultry workers was measured using a spirometer. Along with spirometry, a structured questionnaire was also administrated to obtain information about age, height, weight, smokers/nonsmokers, years of working experience, and pulmonary health of farm workers. The workers who were directly involved in the care and handling of birds in these intensive facilities were considered and divided into four groups based on their years of working experience: Group I (3-10 months), Group II (1-5 years), Group III (6-10 years), and Group IV (more than 11 years). The forced vital capacity (FVC), forced expiratory volume in one second (FEV1) and the FEV1/FVC ratio were considered to identify lung function abnormalities. Statistical analysis was carried out using independent sample t test, Chi-square test, Pearson's correlation, and linear regression.

Results

Based on the performed spirometry, 68 (86 %) of workers were found normal and healthy, whereas 11 (14 %) had a mild obstruction. Of the 11 workers with mild obstruction, the highest number with respect to the total was in Group IV (more than 11 years of working experience) followed by Group III and Group II. Most of the workers were found healthy, which seems to be because of the healthy survivor effect. For the independent sample t test, a significant difference was noticed between healthy and nonhealthy farmers, whereas Chi-square test showed a significant association with height, drugs, and working experience. Linear regression that was stratified by respiratory symptoms showed for workers with symptoms, regression models for all spirometric parameters (FVC, FEV1, and FEV1/FVC) have better predictive power or R square value than those of workers without symptoms.

Conclusion

These findings suggest that lung function capacity was directly related to years of working experience. With increasing number of working years, symptoms of various respiratory problems enhanced in the poultry workers. It should be noted that most of the poultry workers were healthy and young, the rationale being that there is a high turnover rate in this profession. The mobility in this job and our finding of 86% of the healthy workers in the present study also proposed healthy worker survivor effect.

Bovine Allergens in a Ruminant Clinic and Dairy Barns: Exposure Levels, Determinants, and Variability

Background

Dairy farmers may develop specific sensitization and allergic airway diseases due to bovine allergens. However, dose-response relationships are lacking, and as yet little is known on bovine allergen exposure levels.

Objective

To investigate bovine allergen exposure levels in a ruminant clinic and dairy barns, and to assess exposure determinants and variability of exposure.

Methods

Samples were collected using active and passive airborne dust measurements in a ruminant clinic and several dairy barns. Bovine allergen levels were determined by sandwich enzyme-linked immunosorbent assay. Linear mixed models were applied to explore the association between bovine allergen exposure levels and potential exposure determinants. Day-to-day within-worker and between-worker exposure variability was determined, as well as how exposure determinants affect exposure variability.

Results

Bovine allergens were measureable in all samples. Personal bovine allergen exposure levels in the ruminant clinic ranged from 0.10 to 24.8 µg/m3, geometric mean (GM) 1.34 µg/m3. Exposure levels varied dependent on job titles. Personal exposure levels in dairy barns ranged from 0.10 to 46.8 µg/m3, GM 1.47 µg/m3. Type of bedding materials in the barns appeared to be a significant determinant of bovine allergen levels. Compost bedding, particularly, increased allergen levels. Milking by robot was the most important determinant explaining between-worker exposure variability, while bedding was important as well. Bovine allergen levels in stationary measurements were somewhat lower than personal measurements (GM ratio 0.47). Bovine allergens could be readily detected in electrostatic dust-fall collector measurements.

Conclusion

This study provides insight in bovine allergen exposure levels and their determinants, which is a first step to investigate dose-response relationships between sensitization/allergy associated with exposure to bovine allergen levels in future studies.

Allergy Development in Adulthood: An Occupational Cohort Study of the Manufacturing of Industrial Enzymes

BACKGROUND

Occupational allergy may serve as a model of allergy development in adults.

OBJECTIVE

We aimed at describing respiratory allergy and IgE sensitization across different exposure strata defined by time, technology, and exposure control.

METHODS

In a retrospective (1970-2017) cohort of industrial enzyme production employees, monitored by an occupational medical center, 5024 individuals were surveyed. Five exposure groups and risk levels for sensitization and allergic disease were analyzed on the basis of demographic characteristics, hiring decade, and smoking status.

RESULTS

Of all persons entering the company 47 years from 1970, 149 developed occupational allergy (incidence rate, 2.72/1000 person-years). In a multivariate cause-specific Cox proportional hazards model, the hazard of allergy was significantly related to decade of recruitment. Compared with the 1970s, the hazard ratio (HR) uniformly decreased from 0.85 (95% CI, 0.57-1.27) in the 1980s to 0.16 (95% CI, 0.05-0.52) in the 2010s. Compared with expected highest exposed group, the HRs were 0.48 (95% CI, 0.31-76) and 0.13 (95% CI, 0.06-0.30) in less exposed production areas and 0.92 (95% CI, 0.48-1.73) and 0.23 (95% CI, 0.10-0.53) in different laboratory areas. The HR of smoking was 2.03 (95% CI, 1.41-2.93). The pattern of sensitizations also showed clear associations to recruitment decade, exposure, and smoking. Among individuals sensitized but not yet allergic, a high IgE level was the only risk factor (HR, 3.03; 95% CI, 1.82-5.04) for subsequent allergy development.

CONCLUSIONS

The impact of exposure is dose-related and linked to the sensitization step, which may subsequently lead to allergy development. For primary prevention of enzyme allergy, exposure control is mandatory and achievable despite increasing production volumes.

Occupational contact urticaria and protein contact dermatitis: causes and concomitant airway diseases

BACKGROUND

Contact urticaria (CU) and protein contact dermatitis (PCD) are mainly induced by an immediate, IgE-mediated immunological mechanism. Immediate sensitization is also linked to asthma and/or allergic rhinitis.

OBJECTIVES

To report causes of work-induced CU and PCD, and to evaluate the occurrence of concomitant airway diseases.

METHODS

We retrospectively reviewed the patient files of cases diagnosed with CU or PCD at the Finnish Institute of Occupational Health during 1995-2011. We obtained data on occupation, exposures, clinical and immunological test results, and diagnosed occupational skin and respiratory diseases.

RESULTS

Altogether, 291 cases of occupational CU or PCD were diagnosed during the study period. The most common causes were flour, cow dander, natural rubber latex and acid anhydrides. Concomitant occupational asthma caused by the same agent as the skin disease was detected in 60 patients (21%), and occupational rhinitis was detected in 111 patients (38%).

CONCLUSIONS

Almost half of the patients (46%) with occupational CU and PCD had concomitant occupational airway disease. Patients with CU/PCD should always be asked about respiratory symptoms, and preventive measures at the workplace should include protection of both the skin and the airways.

Azodicarbonamide (ADCA): A reconsideration of classification as a respiratory sensitiser

Azodicarbonamide (ADCA) is widely used by industry in the manufacture of a variety of products. ADCA has been classified as a respiratory allergen, and the purpose of this article was to consider whether this classification is appropriate based upon the available data. Here both clinical experience and relevant experimental data have been reviewed. Although there have been reports of an association between workplace exposure to ADCA and symptoms of respiratory allergy and occupational asthma, the evidence is less than persuasive, with in many instances a lack of properly controlled and executed diagnostic procedures. In addition, ADCA fails to elicit positive responses in mouse and guinea pig predictive tests for skin sensitisation; a lack of activity that is regarded as being inconsistent with respect to respiratory sensitising potential. Collectively, the data reviewed here do not provide an adequate basis for the classification of ADCA as a respiratory allergen.

Work-related asthma in a sample of subjects with established asthma

OBJECTIVE

To assess the impact of occupational exposure to irritants or sensitizers on the occurrence, recrudescence and worsening of asthma and to identify unrecognized cases of work related asthma (WRA) including Work-Exacerbated Asthma (WEA) and Occupational Asthma (OA), in a general asthma clinic population sample.

SETTING, DESIGN AND PARTICIPANTS

The study was a population-based cross sectional survey. 1289 asthmatic subjects (from 15 to 46 yrs old) living in a vast district of Tuscany (Italy) were identified from the Medical Reimbursement Register of the National Health System. 893 subjects agreed to take part in the study. Subjects who were currently working or had worked in past were classified in different categories of occupational risk exposure (No, Low or High) according to the italian standard classification for industries and job titles, associated with the judgment of occupational hygiene experts.

RESULTS

41% of subjects worked in industries and in job titles at risk for exposure to airway irritants and/or sensitizers, 48.6% reported an occupational exposure to gases, dust and fumes, more males than females. Prevalence of WEA and OA was higher in subjects who worked at higher risk exposure; these subjects reported a higher prevalence of markers of asthma severity (asthma control, level of treatment, FEV1) than subjects without WRA. Risk of WEA was significantly associated to female gender, older age, and self-reported exposure, while risk of OA was associated to job title with higher exposure risk to occupational asthmogens.

CONCLUSIONS

Our study shows a high prevalence of WRA (especially WEA) associated with employment in industries and job titles at risk for airways sensitizers and/or irritants; data also support a role for occupational exposure in determining a poor asthma control and a higher level of asthma severity.

Occupational Disease Registries-Characteristics and Experiences

INTRODUCTION

Due to growth of occupational diseases and also increase of public awareness about their consequences, attention to various aspects of diseases and improve occupational health and safety has found great importance. Therefore, there is the need for appropriate information management tools such as registries in order to recognitions of diseases patterns and then making decision about prevention, early detection and treatment of them. These registries have different characteristics in various countries according to their occupational health priorities.

AIM

Aim of this study is evaluate dimensions of occupational diseases registries including objectives, data sources, responsible institutions, minimum data set, classification systems and process of registration in different countries.

MATERIAL AND METHODS

In this study, the papers were searched using the MEDLINE (PubMed) Google scholar, Scopus, ProQuest and Google. The search was done based on keyword in English for all motor engines including "occupational disease", "work related disease", "surveillance", "reporting", "registration system" and "registry" combined with name of the countries including all subheadings. After categorizing search findings in tables, results were compared with each other.

RESULTS

Important aspects of the registries studied in ten countries including Finland, France, United Kingdom, Australia, Czech Republic, Malaysia, United States, Singapore, Russia and Turkey. The results show that surveyed countries have statistical, treatment and prevention objectives. Data sources in almost the rest of registries were physicians and employers. The minimum data sets in most of them consist of information about patient, disease, occupation and employer. Some of countries have special occupational related classification systems for themselves and some of them apply international classification systems such as ICD-10. Finally, the process of registration system was different in countries.

CONCLUSION

Because occupational diseases are often preventable, but not curable, it is necessary to all countries, to consider prevention and early detection of occupational diseases as the objectives of their registry systems. Also it is recommended that all countries reach an agreement about global characteristics of occupational disease registries. This enables country to compare their data at international levels.

High occurrence of rhinitis symptoms in hairdressing apprentices

BACKGROUND

Little is known about the occurrence of respiratory symptoms among hairdressing apprentices during their training. Therefore, in this study, we examined whether hairdressing apprentices are at increased risk of rhinitis and asthma symptoms when compared with other young adults from the general population.

METHODS

A questionnaire was completed by 504 hairdressing apprentices and 1400 control participants from the general population with a similar age, gender, and geographic distribution.

RESULTS

The 1-year prevalence of rhinitis symptoms was higher in hairdressing apprentices than in controls (58.1% vs 46.6%; odds ratio, 1.59; 95% confidence interval, 1.30-1.98), and the prevalence was higher among hairdressing apprentices in the last years of training compared with apprentices in the first year of training (62.4% vs 41.8%, p = 0.003). Current smoking was more common in hairdressing apprentices (28.4% vs 17.2%, p < 0.001). Asthma symptoms were equally common in the 2 groups; however, hairdressing apprentices had a later age of onset of wheezing than did the controls (18 years vs 14 years, p < 0.00001) and a decreased risk of wheezing (odds ratio, 0.72; 95% confidence interval, 0.54 to 0.95) after adjusting for smoking, education level, and degree of rurality. Bleaching products were the most frequently reported cause of rhinitis and asthma symptoms in hairdressing apprentices.

CONCLUSIONS

Hairdressing apprentices seem to have an increased risk of occupational rhinitis, and bleaching products are the main cause of respiratory symptoms. In addition, our findings suggest that a healthy worker effect exists in relation to asthma among hairdressing apprentices.

Breath-taking jobs: a case-control study of respiratory work disability by occupation in Norway

Background

The current knowledge on respiratory work disability is based on studies that used crude categories of exposure. This may lead to a loss of power, and does not provide sufficient information to allow targeted workplace interventions and follow-up of patients with respiratory symptoms.

Objectives

The aim of this study was to identify occupations and specific exposures associated with respiratory work disability.

Methods

In 2013, a self-administered questionnaire was mailed to a random sample of the general population, aged 16–50, in Telemark County, Norway. We defined respiratory work disability as a positive response to the survey question: ‘Have you ever had to change or leave your job because it affected your breathing?’ Occupational exposures were assessed using an asthma-specific job-exposure matrix, and comparison of risks was made for cases and a median of 50 controls per case.

Results

247 workers had changed their work because of respiratory symptoms, accounting for 1.7% of the respondents ever employed. The ‘breath-taking jobs’ were cooks/chefs: adjusted OR 3.6 (95% CI 1.6 to 8.0); welders: 5.2 (2.0 to 14); gardeners: 4.5 (1.3 to 15); sheet metal workers: 5.4 (2.0 to 14); cleaners: 5.0 (2.2 to 11); hairdressers: 6.4 (2.5 to 17); and agricultural labourers: 7.4 (2.5 to 22). Job changes were also associated with a variety of occupational exposures, with some differences between men and women.

Conclusions

Self-report and job-exposure matrix data showed similar findings. For the occupations and exposures associated with job change, preventive measures should be implemented.

Twenty years of SHIELD: decreasing incidence of occupational asthma in the West Midlands, UK?

INTRODUCTION

Since 2000 a decline in the incidence of occupational asthma (OA) has been reported in the UK and Europe. We aimed to describe and account for trends in the incidence of OA in the West Midlands, UK using annual notification data from the SHIELD voluntary surveillance scheme over the period 1991-2011.

METHODS

All notifications to the SHIELD database between January 1991 and December 2011 were identified, along with patients' demographic data, occupations, causative agents and confirmatory tests. Annual notifications were scaled to give an annual count per million workers, giving a measure of incidence, and also standardised against those of bakers' asthma. Non-parametric analyses were undertaken between annual incidence and time (years) for common causative agents using (1) a negative binomial regression univariate model and (2) a logistic regression model calculating annual reporting ORs. A step-change analysis was used to examine time points at which there were marked reductions in incidence.

RESULTS

A decrease in annual incidence of OA was observed over the study period (incident rate ratio=0.945; 95% CI 0.933 to 0.957; p<0.0001), an effect that was lost after standardising for bakers' asthma. Decreases in incidence were seen for most common causative agents, with only cleaning product-related OA increasing over 21 years. Marked fall in incidence was seen in 2004 for isocyanates, and in 1995 for latex. Most notifications came from a regional specialist occupational lung disease unit, with notifications from other sites falling from 16 cases/million workers/annum in 1995 to 0 in 2004.

CONCLUSIONS

Reporter fatigue and increasing under-recognition of OA are both factors which contribute to the apparent fall in incidence of OA in the West Midlands. There is a future need for interventions that enable health professionals to identify potential cases of OA in the workplace and in healthcare settings.

Exposure levels, determinants and IgE mediated sensitization to bovine allergens among Danish farmers and non-farmers

BACKGROUND

Bovine allergens can induce allergic airway diseases. High levels of allergens in dust from stables and homes of dairy farmers have been reported, but sparse knowledge about determinants for bovine allergen levels and associations between exposure level and sensitization is available.

OBJECTIVE

To investigate levels and determinants of bovine allergen exposure among dairy, pig and mink farmers (bedroom and stable), and among former and never farmers (bedroom), and to assess the prevalence of bovine allergen sensitization in these groups.

METHODS

In 2007-2008, 410 settled dust samples were collected in stables and in bedrooms using an electrostatic dust-fall collector over a 14 day period among 54 pig farmers, 27 dairy farmers, 3 mink farmers as well as 71 former and 48 never farmers in Denmark. For farmers sampling was carried out both during summer and winter. Bovine allergen levels (μg/m(2)) were measured using a sandwich ELISA. Determinants for bovine allergen exposure in stables and bedrooms were explored with mixed effect regression analyses. Skin prick test with bovine allergen was performed on 48 pig farmers, 20 dairy farmers, 54 former and 31 never farmers.

RESULTS

Bovine allergen levels varied by five orders of magnitude, as expected with substantially higher levels in stables than bedrooms, especially for dairy farmers. Bovine allergen levels in bedrooms were more than one order of magnitude higher for dairy farmers compared to pig farmers. Former and never farmers had low levels of bovine allergens in their bedroom. Bovine allergen levels during summer appeared to be somewhat higher than during winter. Increased bovine allergen levels in the bedroom were associated with being a farmer or living on a farm. Mechanical ventilation in the bedroom decreased bovine allergen level, significant for dairy farmers β=-1.4, p<0.04. No other significant effects of either sampling or residence characteristics were seen. Allergen levels in dairy stables were associated to type of dairy stable, but not to other stable or sampling characteristics. Sensitization to bovine allergens was only found in one pig farmer.

CONCLUSION

This study confirms high bovine allergen levels in dairy farms, but also suggests sensitization to bovine allergens among Danish farmers to be uncommon. Furthermore the importance of a carrier home effect on allergen load is emphasized. Whether the risk for bovine sensitization is related to the allergen level in the stable or the dwelling remains to be determined.

Work-Related Asthma in Korea - Findings from the Korea Work-Related Asthma Surveillance (KOWAS) program, 2004-2009

PURPOSE

To determine the incidence and epidemiological characteristics of work-related asthma in Korea.

METHODS

During 2004-2009, the Korea Work-Related Asthma Surveillance (KOWAS) program collected data on new cases of work-related asthma from occupational physicians, allergy and chest physicians, regional surveillance systems, and workers' compensation schemes. The incidence was calculated on the basis of industry, occupation, sex, age, and region. In addition, the distribution of causal agents was determined.

RESULTS

During the study period, 236 cases of work-related asthma were reported, with 77 cases from more than 1 source. A total of 22.0% (n=52) were reported by occupational physicians, 52.5% (n=124) by allergy and chest physicians, 24.2% (n=57) by regional surveillance systems, and 43.2% (n=102) by workers' compensation schemes. The overall average annual incidence was 3.31 cases/million workers, with a rate of 3.78/million among men and 2.58/million among women. The highest incidence was observed in the 50-59-year age group (7.74/million), in the Gyeonggi/Incheon suburb of Seoul (8.50/million), in the furniture and other instrument manufacturing industries (67.62/million), and among craft and related trades workers (17.75/million). The most common causal agents were isocyanates (46.6%), flour/grain (8.5%), metal (5.9%), reactive dyes (5.1%), and solvents (4.2%).

CONCLUSIONS

The incidence of work-related asthma in Korea was relatively low, and varied according to industry, occupation, gender, age, and region. Data provided by workers' compensation schemes and physician reports have been useful for determining the incidence and causes of work-related asthma.

When to suspect occupational asthma

Occupational asthma (OA) is a difficult diagnosis to make. The present review describes the work environments in which workers are at risk for developing OA, the characteristics of the individuals in whom OA should be suspected and the investigation that can be performed to diagnose the condition. Accurately diagnosing OA is crucial because of the major social and economic consequences of this diagnosis on the patient.

Chemical and biological work-related risks across occupations in Europe: a review

BACKGROUND

Work-related health inequalities are determined to some extent by an unequal exposure to chemical and biological risk factors of disease. Although their potential economic burden in the European Union (EU-25) might be substantial, comprehensive reviews focusing on the distribution of these risks across occupational groups are limited. Thus, the main objective of this review is to provide a synopsis of the exposure to chemical and biological hazards across occupational groups. In addition, main industrial applications of hazardous substances are identified and some epidemiological evidence is discussed regarding societal costs and incidence rates of work-related diseases.

METHODS

Available lists of carcinogens, sensitisers, mutagens, reprotoxic substances and biological hazards were consulted. For each work-related hazard the main industrial application was identified in order to assess which ISCO occupational groups may be associated with direct exposure. Where available, information on annual tonnage production, risk assessment of the substances and pathogens, and other relevant data were collected and reported.

RESULTS

Altogether 308 chemical and biological hazards were identified which may account to at least 693 direct exposures. These hazards concentrate on the following major occupational groups: technicians (ISCO 3), operators (ISCO 8), agricultural workers (ISCO 6) and workers in elementary occupations (ISCO 9). Common industrial applications associated with increased exposure rates relate among others to: (1) production or application of pigments, resins, cutting fluids, adhesives, pesticides and cleaning products, (2) production of rubber, plastics, textiles, pharmaceuticals and cosmetics, and (3) in agriculture, metallurgy and food processing industry, Societal costs of the unequal distribution of chemical and biological hazards across occupations depend on the corresponding work-related diseases and may range from 2900 EUR to 126000 EUR per case/year.

CONCLUSIONS

Risk of exposure to chemical and biological risks and work-related disease incidence are highly concentrated on four occupational groups. The unequal burden of exposure across occupations is an important contributing factor leading to health inequalities in society. The bulk of societal costs, however, are actually being borne by the workers themselves. There is an urgent need of taking into account the health impact of production processes and services on workers' health.

An official American Thoracic Society proceedings: work-related asthma and airway diseases. Presentations and discussion from the Fourth Jack Pepys Workshop on Asthma in the Workplace

Work-related asthma is a common occupational lung disease. The scope of the Fourth Jack Pepys Workshop that was held in May 2010 went beyond asthma to include discussion of other occupational airway diseases, in particular occupationally related chronic obstructive pulmonary disease (COPD) and bronchiolitis. Aspects explored included public health considerations, environmental aspects, outcome after diagnosis, prevention and surveillance, and other work-related obstructive airway diseases. Consistent methods are needed to accurately estimate the comparative burden of occupation-related airway diseases among different countries. Challenges to accomplishing this include variability in health care delivery, compensation systems, cultural contexts, and social structures. These factors can affect disease estimates, while heterogeneity in occupations and workplace exposures can affect the underlying true prevalence of morbidity. Consideration of the working environment included discussion of practical methods of limiting exposure to respiratory sensitizers, methods to predict new sensitizers before introduction into workplaces, the role of legislated exposure limits, and models to estimate relative validity of various ameliorative measures when complete avoidance of the sensitizer is not feasible. Other strategies discussed included medical surveillance measures and education, especially for young individuals with asthma and new workers about to enter the workforce. Medical outcomes after development of sensitizer-induced occupational asthma are best following earlier diagnosis and removal from further exposure, but a subset may be able to continue working safely provided that exposure is reduced under close follow-up monitoring. It was recognized that occupationally related COPD is common but underappreciated, deserving further study and prevention efforts.

Physiological daily inhalation rates for health risk assessment in overweight/obese children, adults, and elderly

Physiological daily inhalation rates reported in our previous study for normal-weight subjects 2.6-96 years old were compared to inhalation data determined in free-living overweight/obese individuals (n = 661) aged 5-96 years. Inhalation rates were also calculated in normal-weight (n = 408), overweight (n = 225), and obese classes 1, 2, and 3 adults (n = 134) aged 20-96 years. These inhalation values were based on published indirect calorimetry measurements (n = 1,069) and disappearance rates of oral doses of water isotopes (i.e., (2)H2 O and H2 (18)O) monitored by gas isotope ratio mass spectrometry usually in urine samples for an aggregate period of over 16,000 days. Ventilatory equivalents for overweight/obese subjects at rest and during their aggregate daytime activities (28.99 ± 6.03 L to 34.82 ± 8.22 L of air inhaled/L of oxygen consumed; mean ± SD) were determined and used for calculations of inhalation rates. The interindividual variability factor calculated as the ratio of the highest 99th percentile to the lowest 1st percentile of daily inhalation rates is higher for absolute data expressed in m3 /day (26.7) compared to those of data in m3/kg-day (12.2) and m3/m2-day (5.9). Higher absolute rates generally found in overweight/obese individuals compared to their normal-weight counterparts suggest higher intakes of air pollutants (in μg/day) for the former compared to the latter during identical exposure concentrations and conditions. Highest absolute mean (24.57 m3/day) and 99th percentile (55.55 m3 /day) values were found in obese class 2 adults. They inhale on average 8.21 m3 more air per day than normal-weight adults.

Gender specific analysis of occupational diseases of the low back caused by carrying, lifting or extreme trunk flexion--use of a prevention index to identify occupations with high prevention needs

BACKGROUND

Gender specific analysis of the occupational disease of the lumbar spine caused by carrying, lifting, or extreme trunk flexion in Germany (OD No.2108) with the aim to identify areas of focus for prevention and research with a prevention index (PI).

METHODS

Data from the German Statutory Accident Insurance stratified by gender are shown.

RESULTS

From 2002 until 2009 there were 2,877 confirmed cases of an OD No. 2108 (40.1% male and 59.1% female). The PI indicated the highest prevention need for female nursing/midwifery associate professionals and male building frame and related trades workers. Patient transfer and working in extremely bent posture were the most frequent exposures.

CONCLUSIONS

The identified occupations with high need for prevention among men come from nearly all major occupational groups whereas women cluster in occupational groups from the health and care sectors.

Occupational diseases in Poland--an overview of current trends

INTRODUCTION

The number of occupational diseases (OD) recorded in Poland in the 1990's rapidly increased, and the number of recognized cases has steadily decreased until now. Hence, it was decided to demonstrate the trends of selected pathologies which in Poland are "underestimated" in comparison to other countries. The presented data may constitute a basis for further research into the dependence of OD on socio-economic factors.

MATERIALS AND METHODS

Occupational Disease Reporting Forms, completed and sent obligatorily by the state health inspectors to the Central Register of Occupational Diseases were used as source documents for analysis. This work analyzes changes in the incidence of chronic poisonings, asbestosis, voice organ diseases, cancers, viral hepatitis, asthma and the musculoskeletal disorders over the years 1998-2011.

RESULTS

In 1998, the total number of registered diseases reached the maximum - 12,017 cases, which fell in the subsequent years to 2,562 cases in 2011. During that period, the incidence rate decreased by 6 cases per year per 100,000 employees. A considerable decrease, exceeding 90% of cases, was observed in voice organ disorders, hearing loss, chronic poisonings and viral hepatitis. The abovementioned changes, as well as improved detection of asbestos-related diseases through implementing a medical examination program of former asbestos processing plant workers, are advantages of the current situation in the epidemiology of OD. However, the disadvantages include underestimation, in comparison to other countries, of asthma, cancer and pathologies of the musculoskeletal system.

CONCLUSION

The reported data indicates the need to assess the occupational fraction of the underestimated pathologies present in the work environment in Poland, as well as the need for studies aimed at clarifying the effect of systemic factors on identifying their occupational background.

Occupational exposure to poultry dust and effects on the respiratory system in workers

Farmers are occupationally exposed to many respiratory hazards at work and display higher rates of asthma and respiratory symptoms than other workers. Dust is one of the components present in poultry production that increases risk of adverse respiratory disease occurrence. Dust originates from poultry residues, molds, and feathers and is biologically active as it contains microorganisms. Exposure to dust is known to produce a variety of clinical responses, including asthma, chronic bronchitis, chronic airways obstructive disease (COPD), allergic alveolitis, and organic dust toxic syndrome (ODTS). A study was developed to determine particle contamination in seven poultry farms and correlate this with prevalence rate of respiratory defects and record by means of a questionnaire the presence of clinical symptoms associated with asthma and other allergy diseases by European Community Respiratory Health Survey. Poultry farm dust contamination was found to contain higher concentrations of particulate matter (PM) PM5 and PM10. Prevalence rate of obstructive pulmonary disorders was higher in individuals with longer exposure regardless of smoking status. In addition, a high prevalence for asthmatic (42.5%) and nasal (51.1%) symptoms was noted in poultry workers. Data thus show that poultry farm workers are more prone to suffer from respiratory ailments and this may be attributed to higher concentrations of PM found in the dust. Intervention programs aimed at reducing exposure to dust will ameliorate occupational working conditions and enhance the health of workers.

Exercise-related respiratory symptoms and exercise-induced bronchoconstriction in industrial bakers

In order to assess prevalence and characteristics of exercise-related respiratory symptoms (ERRS) and exercise-induced bronchoconstriction (EIB) in industrial bakery, the authors performed a cross-sectional study including 57 bakers and an equal number of office workers studied as a control. Evaluation of examined subjects included completion of a questionnaire, skin prick tests to common inhalant and occupational allergens, spirometry, and exercise and histamine challenge. The authors found a similar prevalence of ERRS and EIB in both bakers and controls. EIB was significantly associated with atopy, asthma, family history of asthma, and positive histamine challenge in either group, whereas in bakers it was closely related to sensitization to occupational allergens (p = .032). Bronchial reaction to exercise was significantly higher in bakers with EIB (25.7% vs 19.2%; p = .021). These findings suggest that occupational exposure in industrial bakery may accentuate bronchoconstrictive response to exercise.

Occupation and three-year incidence of respiratory symptoms and lung function decline: the ARIC Study

Background

Specific occupations are associated with adverse respiratory health. Inhalation exposures encountered in these jobs may place workers at risk of new-onset respiratory disease.

Methods

We analyzed data from 8,967 participants from the Atherosclerosis Risk in Communities (ARIC) study, a longitudinal cohort study. Participants included in this analysis were free of chronic cough and phlegm, wheezing, asthma, chronic bronchitis, emphysema, and other chronic lung conditions at the baseline examination, when they were aged 45-64 years. Using data collected in the baseline and first follow-up examination, we evaluated associations between occupation and the three-year incidence of cough, phlegm, wheezing, and airway obstruction and changes in forced expiratory volume in one second (FEV₁) and forced vital capacity (FVC) measured by spirometry. All associations were adjusted for age, cigarettes per day, race, smoking status, and study center.

Results

During the approximately three-year follow-up, the percentage of participants developing chronic cough was 3%; chronic phlegm, 3%; wheezing, 3%; and airway obstruction, defined as FEV₁ < lower limit of normal (LLN) and FEV₁/FVC < LLN, 2%. The average annual declines in FEV₁ and FVC were 56 mL and 66 mL, respectively, among men and 40 mL and 52 mL, respectively, among women. Relative to a referent category of managerial and administrative support occupations, elevated risks of new-onset chronic cough and chronic phlegm were observed for mechanics and repairers (chronic cough: RR: 1.81, 95% CI: 1.02, 3.21; chronic phlegm: RR: 2.10, 95% CI: 1.23, 3.57) and cleaning and building service workers (chronic cough: RR: 1.85, 95% CI: 1.01, 3.37; chronic phlegm: RR: 2.28, 95% CI: 1.27, 4.08). Despite the elevated risk of new-onset symptoms, employment in cleaning and building services was associated with attenuated lung function decline, particularly among men, who averaged annual declines in FEV₁ and FVC of 14 mL and 23 mL, respectively, less than the declines observed in the referent population.

Conclusions

Employment in mechanic and repair jobs and cleaning and building service occupations are associated with increased incidence of respiratory symptoms. Specific occupations affect the respiratory health of adults without pre-existing respiratory health symptoms and conditions, though long-term health consequences of inhalation exposures in these jobs remain largely unexplored.

Assessment of public health impact of work-related asthma

Background

Asthma is among the most common chronic diseases in working-aged populations and occupational exposures are important causal agents. Our aims were to evaluate the best methods to assess occurrence, public health impact, and burden to society related to occupational or work-related asthma and to achieve comparable estimates for different populations.

Methods

We addressed three central questions: 1: What is the best method to assess the occurrence of occupational asthma? We evaluated: 1) assessment of the occurrence of occupational asthma per se, and 2) assessment of adult-onset asthma and the population attributable fractions due to specific occupational exposures. 2: What are the best methods to assess public health impact and burden to society related to occupational or work-related asthma? We evaluated methods based on assessment of excess burden of disease due to specific occupational exposures. 3: How to achieve comparable estimates for different populations? We evaluated comparability of estimates of occurrence and burden attributable to occupational asthma based on different methods.

Results

Assessment of the occurrence of occupational asthma per se can be used in countries with good coverage of the identification system for occupational asthma, i.e. countries with well-functioning occupational health services. Assessment based on adult-onset asthma and population attributable fractions due to specific occupational exposures is a good approach to estimate the occurrence of occupational asthma at the population level. For assessment of public health impact from work-related asthma we recommend assessing excess burden of disease due to specific occupational exposures, including excess incidence of asthma complemented by an assessment of disability from it. International comparability of estimates can be best achieved by methods based on population attributable fractions.

Conclusions

Public health impact assessment for occupational asthma is central in prevention and health policy planning and could be improved by purposeful development of methods for assessing health benefits from preventive actions. Registry-based methods are suitable for evaluating time-trends of occurrence at a given population but for international comparisons they face serious limitations. Assessment of excess burden of disease due to specific occupational exposure is a useful measure, when there is valid information on population exposure and attributable fractions.

Health disparities among occupations in Taiwan: a population study

OBJECTIVES

The first large-scale population survey was conducted in Taiwan to examine if and to what extent health disparities of four major chronic physical conditions exist among occupations.

METHODS

Face-to-face interviews about two risk behaviors (i.e., cigarette and alcohol use) and four major chronic physical conditions (i.e., cardiovascular disease, diabetes, liver disease and asthma) were conducted with 13,741 workers from nine major categories of occupations.

RESULTS

Health disparities among occupations were found based on a series of hierarchical logistic regression analyses after controlling for age, sex and two risk behaviors. In general, prevalence rates of cardiovascular disease among elementary occupations and skilled agricultural and fishery workers were approximately two to four times higher than those among other occupations. The above two occupations and plant and machine operators also had higher prevalence rates in diabetes and liver disease.

CONCLUSIONS

The results concerning health disparities among occupations provide policymakers and researchers with invaluable benchmarks of chronic physical conditions among occupations. The findings also suggest the importance of investigating causal relationship between these diseases and exposures at work, identifying and reducing unique risk factors and hazard exposures experienced by workers and conducting targeted surveillance and health promotion programs for at-risk occupations.

Asthma increase among farmers: a 12-year follow-up

Respiratory disease is a well known health hazard for farmers, but the long-term prognosis is less well known. This is a 12-year follow-up of an investigation of Swedish farmers, most of them dairy farmers. A questionnaire was mailed to all 418 farmers who were alive of the farmers originally participating in 1982. They were invited to an interview, spirometry, and blood sampling. Ninety-one per cent (380) of the farmers, 321 men and 59 women, responded to the questionnaire. The mean age was 56 years for the men and 55 years for the women. Of the group, 10% were smokers, 25% ex-smokers, and 65% had never smoked. The population estimate for asthma in the farmers was 8.9% in 1994 compared to 2% in 1982, and to 5.4%-6.6% in the general population in the region in 1982. Of the asthmatic subjects, one-third had positive RAST tests (radioallergosorbent tests). Almost 90% of the new onset asthma cases since 1982 had non-IgE-mediated asthma. Most of the IgE-mediated asthmatics had had symptoms for many years, while 70% of the non-IgE-mediated asthmatic farmers had no or only wheezing with colds 1982. Two new cases of hypersensitivity pneumonitis were identified, and 7.3% had experienced inhalation fever during the last 12 years. In general, individuals with asthma and chronic bronchitis who had left farming were in better health in 1994 as compared to 1982. In conclusion, farmers have an enhanced risk to develop asthma increasing with age. Asthma in farmers is often non-IgE-mediated.

Reported occupational respiratory diseases in three Spanish regions

BACKGROUND

In 2002, a voluntary registry of occupational respiratory diseases was initiated in the test phase in Asturias, Catalonia, and Navarre (Spain). Based on data from the fully implemented voluntary registry, we assessed the differences in the incidence and characteristics of the diseases reported in the three regions studied and compared them with those notified to the compulsory official system.

METHODS

Physicians whose daily practice includes patients with occupational respiratory diseases were invited to participate. Newly diagnosed cases occurring during 2003 in the work force of the three regions studied were reported on a notification form every 2 months. Data from the compulsory official notification system were obtained from statistics on work-related diseases for possible disability benefits.

RESULTS

Five hundred thirty-three new cases, representing a cumulative incidence of 183.52 (168.27-199.78) per million workers per year, were reported. The number of cases and the incidence, overall and for each disease, causes of the diseases, and the occupations varied considerably between regions. The number of cases reported to the voluntary system was more than threefold greater than the number reported to the compulsory official system.

CONCLUSIONS

The compulsory scheme for reporting occupational respiratory diseases is seriously under-reporting in the three Spanish regions studied. Our voluntary surveillance program, which showed considerable differences in the characteristics and incidence of these diseases among the regions, appears to be more effective.

Occupational asthma: risk factors, diagnosis and preventive measures

In adulthood, new or recurrent asthma is caused by work in approximately 10% of cases. The term occupational asthma is reserved for those cases arising from respiratory hypersensitivity to a specific workplace agent; in others (work-exacerbated asthma) the mechanism is of nonspecific airway irritation on a background of bronchial hyper-reactivity. Some 300 workplace agents are capable of inducing asthma de novo; fortunately, most cases are attributed to a much smaller number to which exposure occurs in a few high-risk occupations. Exposure level is the most important remediable risk factor; the factors governing individual susceptibility are poorly understood. Diagnosis is generally straightforward. Management is rarely pharmacologic and often difficult since the diagnosis incurs important employment and other social consequences.

Early incidence of occupational asthma among young bakers, pastry-makers and hairdressers: design of a retrospective cohort study

Background

Occupational exposures are thought to be responsible for 10-15% of new-onset asthma cases in adults, with disparities across sectors. Because most of the data are derived from registries and cross-sectional studies, little is known about incidence of occupational asthma (OA) during the first years after inception of exposure. This paper describes the design of a study that focuses on this early asthma onset period among young workers in the bakery, pastry making and hairdressing sectors in order to assess early incidence of OA in these "at risk" occupations according to exposure duration, and to identify risk factors of OA incidence.

Methods/Design

The study population is composed of subjects who graduated between 2001 and 2006 in these sectors where they experience exposure to organic or inorganic allergenic or irritant compounds (with an objective of 150 subjects by year) and 250 young workers with no specific occupational exposure. A phone interview focusing on respiratory and 'Ear-Nose-Throat' (ENT) work-related symptoms screen subjects considered as "possibly OA cases". Subjects are invited to participate in a medical visit to complete clinical and lung function investigations, including fractional exhaled nitric oxide (FE_NO) and carbon monoxide (CO) measurements, and to collect blood samples for IgE (Immunoglobulin E) measurements (total IgE and IgE for work-related and common allergens). Markers of oxidative stress and genetic polymorphisms exploration are also assessed. A random sample of 200 "non-cases" (controls) is also visited, following a nested case-control design.

Discussion

This study may allow to describ a latent period between inception of exposure and the rise of the prevalence of asthma symptoms, an information that would be useful for the prevention of OA. Such a time frame would be suited for conducting screening campaigns of this emergent asthma at a stage when occupational hygiene measures and adapted therapeutic interventions might be effective.

Trial registration

Clinical trial registration number is NCT01096537.

Surveillance of Australian workplace Based Respiratory Events (SABRE) in New South Wales

BACKGROUND

The Surveillance of Australian workplace Based Respiratory Events (SABRE) New South Wales (NSW) scheme is a voluntary notification scheme established to determine the incidence of occupational lung diseases in NSW Australia.

AIMS

Data presented in this paper summarize the last 7 years of reporting to SABRE (June 2001 to December 2008).

METHODS

Every 2 months, participating occupational physicians, respiratory physicians and general practitioners (accredited by the NSW WorkCover Authority) reported new cases of occupational lung disease seen in their practices. Data collected include gender, age, causal agent and the occupations and industries believed responsible. Estimated incidence was calculated for each disease.

RESULTS

Three thousand six hundred and fifty-four cases were notified to the scheme, consisting of 3856 diagnoses. Most of the cases were males (76%). Pleural plaques [1218 (28%)] were the most frequently reported condition, followed by mesothelioma [919 (24%)]. Silicosis [90 (2%)] and occupational asthma [OA; 89 (2%)] were the most frequently reported non-asbestos-related diseases. Estimated rates for mesothelioma, diffuse pleural thickening (DPT) and OA were 83, 83 and 5 cases per million employed males per year, respectively. Trades such as carpenters and electricians associated with the building industry, electricity supply and asbestos product manufacture were the most common occupations and industries reported.

CONCLUSIONS

Asbestos-related diseases are the most frequently reported conditions to SABRE NSW. The very low incidence of OA for NSW most likely reflects under-diagnosis as well as under-reporting. Occupational lung disease is still occurring in NSW despite current preventative strategies. The SABRE scheme currently provides the only available information in this area.

The New Zealand workforce survey II: occupational risk factors for asthma

INTRODUCTION

We conducted a cross-sectional population-based survey in New Zealand that collected information on work history, current workplace exposures, and selected health outcomes. We report here the findings on occupational risk factors for asthma symptoms.

METHODS

A random sample of men and women aged 20-64 years were selected from the New Zealand Electoral Roll and invited to take part in a telephone survey. Current asthma was defined as: (i) woken up by shortness of breath in the past 12 months; or (ii) an attack of asthma in the past 12 months; or (iii) currently taking asthma medication. Adult-onset asthma was defined as first attack of asthma at age 18 or over. Prevalence odds ratios (ORs) for all occupations were calculated using logistic regression adjusting for sex, age, smoking, and deprivation.

RESULTS

Totally, 2903 participants were included in the analyses. The prevalence of current asthma was 17% and the prevalence of adult-onset asthma was 9%. Prevalence ORs for current asthma were elevated for ever working as a printer [OR = 2.26; 95% confidence interval (CI) = 1.09-4.66], baker (OR = 1.98; 95% CI = 1.02-3.85), sawmill labourer (OR = 3.26; 95% CI = 1.05-10.16), metal processing plant operator (OR = 2.48; 95% CI = 1.22-5.05), and cleaner (OR = 1.60; 95% CI = 1.09-2.35). Excess risks of adult-onset asthma were also found for ever working as a printer, baker, and sawmill labourer as well as ever-working as a market-oriented animal producer (OR = 1.66; 95% CI = 1.14-2.41), and other agricultural worker (OR = 2.08; 95% CI = 1.03-4.20). A number of occupations not previously considered at high risk for asthma were also identified, including teachers and certain sales professionals.

CONCLUSION

This population-based study has confirmed findings of previous international studies showing elevated risks in a number of high-risk occupations. The strongest risks were consistently observed for printers, bakers, and sawmill labourers. Several occupations were also identified that have not been previously associated with asthma, suggesting that the risk of occupational asthma may be more widely spread across the workforce than previously assumed.

Mortality from infectious pneumonia in metal workers: a comparison with deaths from asthma in occupations exposed to respiratory sensitisers

BACKGROUND

National analyses of mortality in England and Wales have repeatedly shown excess deaths from pneumonia in welders. During 1979-90 the excess was attributable largely to deaths from lobar pneumonia and pneumonias other than bronchopneumonia, limited to men of working age and apparent in other occupations with exposure to metal fumes. The findings for 1991-2000 were assessed and compared with the mortality pattern from asthma in occupations exposed to known respiratory sensitisers.

METHODS

The Office of National Statistics supplied data on deaths by underlying cause among men aged 16-74 years in England and Wales during 1991-2000, including age and last held occupation. Data were abstracted on pneumonia for occupations with exposure to metal fumes and on asthma for occupations commonly reported to surveillance schemes as at risk of occupational asthma. The expected numbers of deaths were estimated by applying age-specific proportions of deaths by cause in the population to the total deaths by age in each occupational group. Observed and expected numbers were compared for each cause of death.

RESULTS

Among men of working age in occupations with exposure to metal fumes there was excess mortality from pneumococcal and lobar pneumonia (54 deaths vs 27.3 expected) and from pneumonias other than bronchopneumonia (71 vs 52.4), but no excess from these causes at older ages or from bronchopneumonia at any age. The attributable mortality from metal fume exposure was 45.3 excess deaths compared with an estimated 62.6 deaths from occupational asthma.

CONCLUSION

Exposure to metal fumes is a material cause of occupational mortality. The hazard deserves far more attention than it presently receives.

A pilot asthma incidence surveillance system and case definition: lessons learned

OBJECTIVES

Surveillance for incident asthma in the general population could provide timely information about asthma trends and new, emerging etiologic factors. We sought to determine the feasibility of an asthma incidence surveillance system using voluntary reporting of asthma by outpatient clinics and emergency departments (EDs).

METHODS

Voluntary reporting occurred from July 2002 through June 2006. We classified reported asthma based on a case definition adapted from one developed by the Council of State and Territorial Epidemiologists. We validated the case definition by having pulmonologists review data from participant interviews, medical record abstractions, and pulmonary function test (PFT) results.

RESULTS

The positive predictive value (PPV) of meeting any of the case definition criteria for asthma was 80% to 82%. The criterion of taking at least one rescue and one controller medication had the highest PPV (97% to 100%). Only 7% of people meeting the incident case definition had a PFT documented in their medical record, limiting the usefulness of PFT results for case classification. Compared with pediatric participants, adult participants were more likely to be uninsured and to obtain asthma care at EDs. The surveillance system cost $5129 per enrolled person meeting the incident case definition and was difficult to implement in participating clinics and EDs because asthma reporting was not mandatory and informed consent was necessary.

CONCLUSIONS

The project was useful in evaluating the case definition's validity and in describing the participants' characteristics and health-care use patterns. However, without mandatory reporting laws, reporting of incident asthma in the general population by clinicians is not likely to be a feasible method for asthma surveillance.

Exposure to allergens of different cattle breeds and their relevance in occupational allergy

Introduction

Cattle are an important source of allergens in the working area of farmers. Asthma caused by cow allergens is a significant occupational problem. Yet in allergological testing, the results of in vivo and in vitro diagnostic tests are often inconsistent even in cases with clearly cattle-related symptoms.

Objectives and methods

The aim of this study was to investigate four different commercial cow allergen extracts and to compare them with self prepared extracts of different cattle breeds by means of SDS-PAGE and immunoblotting using the sera of 42 German farmers with asthma and rhino-conjunctivitis caused by cattle contact.

Results

The commercial extracts investigated in this study showed only minor differences in protein pattern. Using sera in immunoblotting experiments distinct bands were found for all symptomatic farmers, even in 13 farmers with a negative result in commercially available serological allergy tests. Bands with molecular weights in the range between about 11 and 67 kDa were observed; reactivity with the major allergen Bos d 2 at about 20 kDa was detected in all farmers, although it was not the strongest band in all cases.

Conclusions

We demonstrate for the first time the allergenic relevance of additional proteins with molecular weights of 14, 30, 55 and approx. 67–97 kDa in more than 50% of farmers with cattle related symptoms. One of our most striking results was that 32% of the investigated farmers with cattle related symptoms showed negative results with commercial serological tests but distinct reactions with cow allergen in immunoblotting experiments. The Bos d 2 content in hair showed differences between certain breeds whereas German Brown and Simmental had particularly higher quantities of Bos d 2 in their hair than breeds such as Holstein-Friesian. These results strongly support the following recommendation: test results with commercial extracts that are contradictory to the clinical symptoms should be supplemented by skin tests using extracts of the hair of the farmers’ own cattle.

Prevalence of asthma among youth on Hispanic-operated farms in the United States-2000

The objective of this study was to estimate prevalence of asthma and asthma attacks among youth (0-19 years old) working and/or living on Hispanic-operated farms. The 2000 U.S. Minority Farm Operator Childhood Agricultural Injury Survey (M-CAIS) data were used to calculate prevalence of asthma, asthma attacks and serious asthma attacks among youth (0 to 19 years) living on Hispanic-operated farms. Age-specific asthma prevalence rates with corresponding 95% confidence intervals (CIs) were calculated for working and nonworking youth. In 2000, an estimated 17,573 youth lived on Hispanic-operated farms; 7.4% had asthma ever diagnosed, 8.1% had an asthma attack while at work in the last year, and 1.4% had a serious asthma attack. Asthma prevalence was highest among youth aged 16-19 (9.1%), males (8.6%), and those driving tractors (9.7%). Serious asthma attacks that required an emergency room visit or hospitalization in the last year were most prevalent among youth aged 0-9 years (1.8%), males (1.7%), and those riding horses (1.7%). Compared with nonworking youth, prevalence of asthma (8.9% versus 6.1%; <i>p</i> < .05) and serious asthma attacks (1.6% versus 1.3%; <i>p</i> > .05) was higher among working youth. Prevalence of asthma attacks in the last year while at work was also significantly higher among males than females (8.6% versus 6.0%; <i>p</i> < .05) and among youth living on livestock farms than among youth on crop farms (9.4% versus 7.4%; <i>p</i> < .05). These findings contribute to the limited information on asthma among youth working on Hispanic-operated farms, and indicate the need for asthma prevention programs on farms and intervention studies targeting farming youth populations.

[The Incidence of occupational asthma in Alsace from 2001 to 2002. Results of intensification of the ONAP project in Alsace (2001-2002). Regional specificities]

INTRODUCTION

A national surveillance programme (ONAP project) was created in France in 1996 by two professional societies to estimate the incidence and identity the characteristics of occupational asthma.

MATERIALS AND METHODS

In 2001 and 2002 chest physicians and occupational physicians in Alsace were intensively solicited for better voluntary reporting of cases of occupational asthma. The objective of this study was to evaluate the consequences of such a procedure on the number of cases reported, with a view to collecting comprehensive data.

RESULTS

The mean annual incidence of occupational asthma was estimated at 126 cases per million workers with a female predominance (52.4%). Flours and isocyanates represented 40% of the suspected agents. Isocyanate asthma (21% of the total) was reported mainly in workers in the car supply industry, and seems to be a specific feature of the region. Persulfates represented 5.3% of the cases; latex and aldehydes 2.6%. The study also points to emergent aetiologies and work risks, i.e. quaternary ammonium compounds in disinfecting detergent products used by cleaners and healthcare workers.

CONCLUSION

This study, which allowed better assessment of the real incidence of OA in Alsace and better detection of substances and occupations at risk, is an incentive to continue our Surveillance programme.

Fifteen-year trends in occupational asthma: data from the Shield surveillance scheme

BACKGROUND

Trends of occupational asthma (OA) differ between regions depending on local industries, provisions for health and safety at the workplace and the availability of a reporting scheme to help in data collection and interpretation.

AIM

To assess trends in OA in an industrialized part of the UK over a 15-year period.

METHODS

Occupational and chest physicians in the West Midlands were invited to submit details of newly diagnosed cases with OA. Data were then transferred to the regional centre for occupational lung diseases for analysis.

RESULTS

A total of 1461 cases were reported to the scheme. Sixty-eight per cent were males with mean (standard deviation) age of 44 (12) years. The annual incidence of OA was 42 per million of working population (95% CI = 37-45). OA was most frequently reported in welders (9%) and health care-related professions (9%) while < 1% of cases were reported in farmers. Isocyanates were the commonest offending agents responsible for 21% of reports followed by metal working fluids (MWFs) (11%), adhesives (7%), chrome (7%), latex (6%) and glutaraldehyde (6%). Flour was suspected in 5% of cases while laboratory animals only in 1%.

CONCLUSIONS

Our data confirm a high annual incidence of OA in this part of the UK. MWFs are an emerging problem, while isocyanates remain the commonest cause. Incidence remained at a fairly stable background level with many small and a few large epidemics superimposed. Schemes like Midland Thoracic Society's Rare Respiratory Disease Registry Surveillance Scheme of Occupational Asthma could help in identifying outbreaks by linking cases at the workplace.

Pesticides and atopic and nonatopic asthma among farm women in the Agricultural Health Study

RATIONALE

Risk factors for asthma among farm women are understudied.

OBJECTIVES

We evaluated pesticide and other occupational exposures as risk factors for adult-onset asthma.

METHODS

Studying 25,814 farm women in the Agricultural Health Study, we used self-reported history of doctor-diagnosed asthma with or without eczema and/or hay fever to create two case groups: patients with atopic asthma and those with nonatopic asthma. We assessed disease-exposure associations with polytomous logistic regression.

MEASUREMENTS AND MAIN RESULTS

At enrollment (1993-1997), 702 women (2.7%) reported a doctor's diagnosis of asthma after age 19 years (282 atopic, 420 nonatopic). Growing up on a farm (61% of all farm women) was protective for atopic asthma (odds ratio [OR], 0.55; 95% confidence interval [CI], 0.43-0.70) and, to a lesser extent, for nonatopic asthma (OR, 0.83; 95%CI, 0.68-1.02; P value for difference = 0.008). Pesticide use was almost exclusively associated with atopic asthma. Any use of pesticides on the farm was associated only with atopic asthma (OR, 1.46; 95% CI, 1.14-1.87). This association with pesticides was strongest among women who had grown up on a farm. Women who grew up on farms and did not apply pesticides had the lowest overall risk of atopic asthma (OR, 0.41; 95% CI, 0.27-0.62) compared with women who neither grew up on farms nor applied pesticides. A total of 7 of 16 insecticides, 2 of 11 herbicides, and 1 of 4 fungicides were significantly associated with atopic asthma; only permethrin use on crops was associated with nonatopic asthma.

CONCLUSIONS

These findings suggest that pesticides may contribute to atopic asthma, but not nonatopic asthma, among farm women.

[Epidemiology and etiologic agents of occupational asthma]

INTRODUCTION

Occupational asthma is, by definition, a disease that can be prevented through appropriate protective strategies. Epidemiological information is required to guide these interventions, and we here examine epidemiological data on the burden, causes, and risk factors for this condition.

STATE OF THE ART

Population-based surveys indicate that approximately 15% of adult asthma is attributable to the workplace environment. The most common occupational agents implicated include flour, isocyanates, latex, and persulphate salts. The occupations in which occupational asthma has been most commonly reported are bakers, spray painters, health-care workers, hairdressers, and cleaners. The level of exposure to sensitizing agents seems to be the most relevant risk factor. Atopy is a significant risk factor only for the development of sensitization to high molecular weight agents. The role of other individual determinants, such as genetic factors, has been less consistently established. Occupational asthma is associated with a substantial adverse impact on the employment and financial status of affected workers.

PERSPECTIVES

Methodological improvements are required in order to distinguish more accurately between occupational and work-exacerbated asthma. Further investigations of the effectiveness of primary and secondary preventive interventions are also needed.