The distribution of breast density in women aged 18 years and older

PURPOSE

Age and body mass index (BMI) are critical considerations when assessing individual breast cancer risk, particularly for women with dense breasts. However, age- and BMI-standardized estimates of breast density are not available for screen-aged women, and little is known about the distribution of breast density in women aged < 40. This cross-sectional study uses three different modalities: optical breast spectroscopy (OBS), dual-energy X-ray absorptiometry (DXA), and mammography, to describe the distributions of breast density across categories of age and BMI.

METHODS

Breast density measures were estimated for 1,961 Australian women aged 18-97 years using OBS (%water and %water + %collagen). Of these, 935 women had DXA measures (percent and absolute fibroglandular dense volume, %FGV and FGV, respectively) and 354 had conventional mammographic measures (percent and absolute dense area). The distributions for each breast density measure were described across categories of age and BMI.

RESULTS

The mean age was 38 years (standard deviation = 15). Median breast density measures decreased with age and BMI for all three modalities, except for DXA-FGV, which increased with BMI and decreased after age 30. The variation in breast density measures was largest for younger women and decreased with increasing age and BMI.

CONCLUSION

This unique study describes the distribution of breast density measures for women aged 18-97 using alternative and conventional modalities of measurement. While this study is the largest of its kind, larger sample sizes are needed to provide clinically useful age-standardized measures to identify women with high breast density for their age or BMI.

The impact of height and weight on rescreening rates within a population-based breast screening program

INTRODUCTION

Women with obesity are at increased risk of post-menopausal breast cancer and less likely to participate in breast screening. This study investigates the impact of asking women their height and weight within a population-based screening program, and the association of BMI with rescreening status.

METHODS

Data regarding 666,130 screening events from 318,198 women aged 50-74 attending BreastScreen Western Australia between 2016 and 2021 were used to compare crude and age-standardised rescreening rates over time. Mixed effects logistic regression was used to investigate associations of BMI with rescreening status.

RESULTS

Rescreening rates for women screened since 2016 were within 1.8% points from the previous reporting period, stratified by screening round. Increasing BMI was associated with decreased likelihood of returning to breast screening (OR = 0.993, 95% CI: 0.988-0.998; OR = 0.989, 95% CI: 0.984-0.994; OR = 0.985, 95% CI: 0.982-0.987 for women screening for the first, second and third+ time, respectively).

CONCLUSIONS

This large, prospective study supports implementation of routine height and weight collection within breast screening programs. It shows that asking women their height and weight does not deter them from returning to screening and that women with increased BMI are less likely to rescreen, highlighting a need for targeted interventions to improve screening barriers for women living with obesity.

Does OSA Increase Risk for Cancer?: A Large Historical Sleep Clinic Cohort Study

BACKGROUND

The relationship between OSA and cancer is unclear.

RESEARCH QUESTION

What is the association between OSA and cancer prevalence and incidence in a large Western Australian sleep clinic cohort (N = 20,289)?

STUDY DESIGN AND METHODS

OSA severity was defined by apnea-hypopnea index (AHI) and nocturnal hypoxemia (duration and percentage at oxygen saturation < 90%) measured by in-laboratory polysomnogram. Measures of potential confounding included age, sex, BMI, smoking status, socioeconomic status, and BP. Outcomes were determined from the Western Australian cancer and death registries. Analyses were confined within periods using consistent AHI scoring criteria: January 1, 1989, to July 31, 2002 (American Sleep Disorders Association criteria), and August 1, 2002, to June 30, 2013 (Chicago criteria). We examined associations of AHI and nocturnal hypoxemia with cancer prevalence using logistic regression and cancer incidence using Cox regression analyses.

RESULTS

Cancer prevalence at baseline was 329 of 10,561 in the American Sleep Disorders Association period and 633 of 9,728 in the Chicago period. Nocturnal hypoxemia but not AHI was independently associated with prevalent cancer following adjustment for participant age, sex, BMI, smoking status, socioeconomic status, and BP. Of those without prevalent cancer, cancer was diagnosed in 1,950 of 10,232 (American Sleep Disorders Association) and 623 of 9,095 (Chicago) participants over a median follow-up of 11.2 years. Compared with the reference category (no OSA, AHI < 5 events per hour), univariable models estimated higher hazard ratios for cancer incidence for mild (AHI 5-15 events per hour), moderate (AHI 15.1-30 events per hour), and severe (AHI > 30 events per hour) OSA. Multivariable analyses consistently revealed associations between age and, in some cases, sex, BMI, and smoking status, with cancer incidence. After adjusting for confounders, multivariable models showed no independent association between OSA severity and increased cancer incidence.

INTERPRETATION

Nocturnal hypoxemia is independently associated with prevalent cancer. OSA severity is associated with incident cancer, although this association seems secondary to other risk factors for cancer development. OSA is not an independent risk factor for cancer incidence.

Alternative methods to measure breast density in younger women

BACKGROUND

Breast density is a strong and potentially modifiable breast cancer risk factor. Almost everything we know about breast density has been derived from mammography, and therefore, very little is known about breast density in younger women aged <40. This study examines the acceptability and performance of two alternative breast density measures, Optical Breast Spectroscopy (OBS) and Dual X-ray Absorptiometry (DXA), in women aged 18-40.

METHODS

Breast tissue composition (percent water, collagen, and lipid content) was measured in 539 women aged 18-40 using OBS. For a subset of 169 women, breast density was also measured via DXA (percent fibroglandular dense volume (%FGV), absolute dense volume (FGV), and non-dense volume (NFGV)). Acceptability of the measurement procedures was assessed using an adapted validated questionnaire. Performance was assessed by examining the correlation and agreement between the measures and their associations with known determinants of mammographic breast density.

RESULTS

Over 93% of participants deemed OBS and DXA to be acceptable. The correlation between OBS-%water + collagen and %FGV was 0.48. Age and BMI were inversely associated with OBS-%water + collagen and %FGV and positively associated with OBS-%lipid and NFGV.

CONCLUSIONS

OBS and DXA provide acceptable and viable alternative methods to measure breast density in younger women aged 18-40 years.

The changing profile of obstructive sleep apnea: long term trends in characteristics of patients presenting for diagnostic polysomnography

Introduction

We aimed to analyze long-term trends in characteristics of patients undergoing diagnostic polysomnography (PSG) and subsequently diagnosed with obstructive sleep apnea (OSA) to inform delivery of sleep services.

Material and Methods

We studied 24,510 consecutive patients undergoing PSG at a tertiary-care sleep service between 1989 and 2013. OSA was defined by an apnea hypopnea index (AHI)≥ 5 events/hour. Changes to hypopnea definition and flow sensing techniques in 2002 created two distinct AHI scoring periods: American Sleep Disorders Association (ASDA) 1989 - July 2002 and American Academy of Sleep Medicine (Chicago) from August 2002.

Results

Over 23.5 years there was a steady increase in proportion of females (15% to 45%), small increases in average age and BMI, and a small decline in socioeconomic status in the overall group. AHI varied between scoring periods both overall [ASDA 10.8/h (3.2-29.6), Chicago 24.3/h (11.8-48.1)] and in the large subgroup (80.7%) diagnosed with OSA [ASDA 20.7/h (10.6-44.1), Chicago 27.4/h (14.8-51.5)]. OSA diagnosis rates increased in the Chicago period (ASDA 66%, Chicago 91%). Increases in AHI and proportion diagnosed appeared better explained by changes in scoring methods than key OSA risk factors.

Conclusion

Temporal increases in proportion of females and decreases in socioeconomic status of people undergoing PSG may reflect greater community awareness of sleep disorders. Temporal increases in age and obesity are consistent with secular trends. Changes in scoring methods have major impacts on OSA diagnosis and judgement of disease severity, with important implications for contemporary resourcing of sleep services and interpretation of historical OSA data.

Post-mammographic screening behaviour: A survey investigating what women do after being told they have dense breasts

ISSUE ADDRESSED

Despite widespread calls for women undergoing mammographic screening to be informed of their breast density, concerns remain as to how this is interpreted and acted upon given the absence of evidence-based supplemental screening recommendations for women with dense breasts. This study investigates the action women take in response to being notified they have dense breasts and what subsequent advice women receive from health professionals.

METHODS

Via a survey of nearly 7000 women, we assessed the post-screening actions of women attending a population-based mammographic screening program (BreastScreen) in Western Australia from 21 November 2017 to 19 April 2018. Women who reported that they were notified they had dense breasts were compared to controls (where applicable). Descriptive and logistic regression analyses were used to summarise responses from 6,183 women.

RESULTS

Half of women notified that they have dense breasts consulted or intended to consult their General Practitioner (GP), particularly those notified for the first time (55%). Of those notified women who consulted their GP, 50% were referred to have supplemental screening. Overall, 20% of women notified as having dense breasts reported that they had an ultrasound due to their breast density.

CONCLUSION

Self-reported health service usage after mammographic screening is higher in women who have been notified they have dense breasts. So what? There is growing pressure for screening programs in Australia and internationally to routinely measure and report breast density to participants. Results from this study can inform screening programs of the likely impact of breast density notification on health service usage. While more information is needed to fill knowledge gaps in recommended action for women with dense breasts, the greatest risks to women arise from not being screened. Hence, health promotion practitioners and health providers should continue to encourage women to participate in BreastScreen programs.

Measurement challenge: protocol for international case-control comparison of mammographic measures that predict breast cancer risk

INTRODUCTION

For women of the same age and body mass index, increased mammographic density is one of the strongest predictors of breast cancer risk. There are multiple methods of measuring mammographic density and other features in a mammogram that could potentially be used in a screening setting to identify and target women at high risk of developing breast cancer. However, it is unclear which measurement method provides the strongest predictor of breast cancer risk.

METHODS AND ANALYSIS

The measurement challenge has been established as an international resource to offer a common set of anonymised mammogram images for measurement and analysis. To date, full field digital mammogram images and core data from 1650 cases and 1929 controls from five countries have been collated. The measurement challenge is an ongoing collaboration and we are continuing to expand the resource to include additional image sets across different populations (from contributors) and to compare additional measurement methods (by challengers). The intended use of the measurement challenge resource is for refinement and validation of new and existing mammographic measurement methods. The measurement challenge resource provides a standardised dataset of mammographic images and core data that enables investigators to directly compare methods of measuring mammographic density or other mammographic features in case/control sets of both raw and processed images, for the purposes of the comparing their predictions of breast cancer risk.

ETHICS AND DISSEMINATION

Challengers and contributors are required to enter a Research Collaboration Agreement with the University of Melbourne prior to participation in the measurement challenge. The Challenge database of collated data and images are stored in a secure data repository at the University of Melbourne. Ethics approval for the measurement challenge is held at University of Melbourne (HREC ID 0931343.3).

Does the Size of a Company Make a Difference in the Prevalence of Exposure to Asthmagens and in the Use of Respiratory Protective Equipment?

Introduction

About half of all workers in high-income countries work in small companies. However, regulatory bodies and researchers predominantly work with large companies because they are more convenient to study and easier to reach. We aimed to estimate the prevalence of exposure to asthmagens and the use of respiratory protective equipment (RPE) by company size.

Methods

This analysis used data from the Australian Work Exposures Study-Asthma, a telephone survey which investigated exposure to 27 asthmagen groups.

Results

Among 4844 respondents, 18.8, 19.9, 31.9, and 29.4% of workers reported working in micro (<5 employees), small (5-19 employees), medium (20-200 employees), and large (>200 employees) companies, respectively. Compared to workers in large companies, workers in micro, small, or medium companies had higher prevalence of exposure to most asthmagens and lesser use of RPE.

Conclusion

Our results suggest that policy actions and regulatory measures should target micro/small companies in order to have the greatest effect.

Measuring height and weight as part of routine mammographic screening for breast cancer

Objectives

Body mass index is a strong predictor of post-menopausal breast cancer risk and (negatively) confounds the association between mammographic breast density and breast cancer risk; however, height and weight are not typically measured as part of routine mammographic screening. This study piloted voluntary height and weight measurement within the BreastScreen Western Australia (WA) programme, and assessed trial participation.

Methods

From February 2016 to January 2018, 204,429 women attending BreastScreen WA were invited to have their height and weight measured and recorded as part of their routine screening mammogram. Descriptive data analysis was used to assess pilot participation rates by available screening data.

Results

Of the 204,429 patients who attended BreastScreen WA during the pilot, 76.35% (156,072) agreed to have their height and weight measured. Pilot participation rates were significantly lower in those patients with disabilities (RR: 0.626; 95% CI: 0.600, 0.653), those who spoke a language other than English at home (RR: 0.876; 95% CI: 0.867, 0.885), and those who identified as Aboriginal and Torres Strait Islander (RR: 0.829; 95% CI: 0.807, 0.852). Pilot participation decreased over time from 88.9% in the first three months to 55.5% in the last month, due to lessening of support from BreastScreen staff.

Conclusion

Measuring height and weight at the time of routine mammographic screening is feasible, although logistical issues, particularly the added time/effort required of support staff, should be considered. BreastScreen WA has since decided to collect voluntary self-reported height and weight data as routine screening policy.

The association between mammographic density and breast cancer risk in Western Australian Aboriginal women

PURPOSE

Mammographic density is an established breast cancer risk factor within many ethnically different populations. The distribution of mammographic density has been shown to be significantly lower in Western Australian Aboriginal women compared to age- and screening location-matched non-Aboriginal women. Whether mammographic density is a predictor of breast cancer risk in Aboriginal women is unknown.

METHODS

We measured mammographic density from 103 Aboriginal breast cancer cases and 327 Aboriginal controls, 341 non-Aboriginal cases, and 333 non-Aboriginal controls selected from the BreastScreen Western Australia database using the Cumulus software program. Logistic regression was used to examine the associations of percentage dense area and absolute dense area with breast cancer risk for Aboriginal and non-Aboriginal women separately, adjusting for covariates.

RESULTS

Both percentage density and absolute dense area were strongly predictive of risk in Aboriginal women with odds per adjusted standard deviation (OPERAS) of 1.36 (95% CI 1.09, 1.69) and 1.36 (95% CI 1.08, 1.71), respectively. For non-Aboriginal women, the OPERAS were 1.22 (95% CI 1.03, 1.46) and 1.26 (95% CI 1.05, 1.50), respectively.

CONCLUSIONS

Whilst mean mammographic density for Aboriginal women is lower than non-Aboriginal women, density measures are still higher in Aboriginal women with breast cancer compared to Aboriginal women without breast cancer. Thus, mammographic density strongly predicts breast cancer risk in Aboriginal women. Future efforts to predict breast cancer risk using mammographic density or standardize risk-associated mammographic density measures should take into account Aboriginal status when applicable.

The distribution and determinants of mammographic density measures in Western Australian aboriginal women

Background

Mammographic density (MD) is an established risk factor for breast cancer. There are significant ethnic differences in MD measures which are consistent with those for corresponding breast cancer risk. This is the first study investigating the distribution and determinants of MD measures within Aboriginal women of Western Australia (WA).

Methods

Epidemiological data and mammographic images were obtained from 628 Aboriginal women and 624 age-, year of screen-, and screening location-matched non-Aboriginal women randomly selected from the BreastScreen Western Australia database. Women were cancer free at the time of their mammogram between 1989 and 2014. MD was measured using the Cumulus software. Kolmogorov-Smirnov tests were used to compare distributions of absolute dense area (DA), precent dense area (PDA), non-dense area (NDA) and total breast area between Aboriginal and non-Aboriginal women. General linear regression was used to estimate the determinants of MD, adjusting for age, NDA, hormone therapy use, family history, measures of socio-economic status and remoteness of residence for Aboriginal and non-Aboriginal women separately.

Results

Aboriginal women were found to have lower DA and PDA and higher NDA than non-Aboriginal women. Age (p <  0.001) was negatively associated and several socio-economic indices (p <  0.001) were positively associated with DA and PDA in Aboriginal and non-Aboriginal women. Remoteness of residence was associated with both mammographic measures but for non-Aboriginal women only.

Conclusions

Aboriginal women have, on average, less MD than non-Aboriginal women but the factors associated with MD are similar for both sample populations. Since reduced MD is associated with improved sensitivity of mammography, this study suggests that mammographic screening is a particularly good test for Australian Indigenous women, a population that suffers from high breast cancer mortality.

Electronic supplementary material

The online version of this article (10.1186/s13058-019-1113-4) contains supplementary material, which is available to authorized users.

The prevalence of exposure to high molecular weight asthmagens derived from plants among workers in Australia

BACKGROUND

Limited information is available on exposure to high molecular weight (HMW) asthmagens derived from plants and on the main occupations and tasks that result in such exposure among workers.

METHODS

Data were collected as part of the Australian Work Exposures Study-Asthma. We estimated adjusted prevalence ratios (aPR) using modified Poisson regression models to determine which factors were associated with exposure.

RESULTS

A 12.8% of 4878 workers were exposed to HMW asthmagens derived from plants. The highest prevalence of exposure was found among farmers/animal workers, education workers, and food processing workers. The main circumstances of exposure were through handling flour, freesias, or through raising livestock. Exposure was more common among female workers (aPR = 1.26, 1.10-1.43) than males, while it was lower among workers born overseas (aPR = 0.70, 0.57-0.86) than those born in Australia.

CONCLUSION

Prevention of exposure to HMW asthmagens derived from plants requires a broad strategy targeting different tasks and occupations.

Workplace psychosocial stressors experienced by migrant workers in Australia: A cross-sectional study

OBJECTIVE

To explore work-related psychosocial stressors among people of Chinese, Vietnamese and Arabic-speaking backgrounds currently working in Australia.

METHODS

In 2015, a telephone survey of 585 Vietnamese, Chinese and Arabic-speaking workers asked about workplace bullying, ethnic discrimination, job complexity, degree of control, security and fairness of payment along with demographic and employment information. Estimates of job-related psychosocial stressors were derived and regression analyses used to identify significant associations.

RESULTS

At least one workplace stressor was reported by 83% of the workers in the study. Education was significantly associated with experiencing any psychosocial stressor and also with the total number of stressors. Workers aged 45 years and older were more likely to be bullied or experience racial discrimination compared with younger workers of any ethnicity. There was a greater likelihood of reporting low control over a job when the interview was conducted in a language other than English and the workers were either Chinese or Arabic. Workers on a fixed-term contract, independent of ethnicity were more likely to report a job with low security. Overall psychosocial job quality decreased with education and was associated with occupation type which interacted with ethnicity and gender.

CONCLUSIONS

The results suggest that job-related psychosocial stressors are widespread but not uniform across ethnic groups. Further research into what drives differences in work experience for migrant groups would provide information to guide both employers and migrants in ways to reduce workplace psychosocial stressors.

Latex glove use among healthcare workers in Australia

BACKGROUND

Exposure to natural rubber latex, primarily through the use of gloves, is a well-recognized cause of occupational asthma. We investigated latex glove use among Australian workers and estimated the resultant burden of occupational asthma among healthcare workers (HCWs).

METHODS

Data were collected in 2014 as part of the Australian Work Exposures Study-Asthma, a telephone survey investigating the prevalence of current occupational exposure to asthmagens, including latex. We estimated adjusted prevalence ratios (aPRs) to determine variables associated with the use of latex gloves among HCWs and calculated the asthma-related disability-adjusted life years due to latex exposure among HCWs.

RESULTS

Latex gloves were used by 22% of respondents. Almost two-thirds (63%) of HCWs reported wearing latex gloves, with 26% using powdered latex gloves. The use of latex gloves was more common among those employed in micro companies (less than 5 employees) than large companies (200+ employees) (aPR = 1.5, 95% confidence interval 1.1-2.0). Latex exposure in HCWs was estimated to contribute 3% of the total asthma-related burden.

DISCUSSION

Latex gloves are widely used by Australian workers and by HCWs in particular.

CONCLUSIONS

This is the first estimate of the burden of asthma attributable to occupational exposure to latex among HCWs. These results can be used to guide decisions regarding the control of occupational exposure to latex.

Prevalence of exposure to occupational carcinogens among farmers

INTRODUCTION

Farmers experience a range of carcinogenic exposures, including some pesticides, fuels, engine exhausts, metals, some organic solvents, silica, wood dusts and solar radiation. However many studies investigating the risk of cancer in farmers focus on pesticide exposure alone. The aim of this study was to determine which carcinogens Australian farmers are exposed to, the prevalence and circumstances of those exposures, and the use of protective equipment.

METHODS

The study used data from the Australian Work Exposures Study (AWES) a cross-sectional study conducted in 2012 that investigated the prevalence of carcinogen exposure among Australian workers. This was supplemented with data from AWES-Western Australia (WA), conducted in 2013, which followed the same methodology but in Western Australian workers only. A total of 5498 Australian workers were interviewed about the tasks they carry out in their workplace. The 166 participants who worked in farming (126 men and 40 women, with an age range of 18-65 years) are the focus of this article.

RESULTS

On average, farmers had been exposed to five different carcinogens. Highest numbers of exposures occurred among men and those working on mixed crop and livestock farms. Solar radiation, diesel engine exhaust and certain solvents were the most prevalent exposures, each with over 85% of farmers exposed. The main tasks leading to exposure were working outdoors, using and repairing farming equipment and burning waste. Sun protection and closed cabs on machinery were the most frequently used forms of protection.

CONCLUSIONS

Farmers are a high risk group in relation to carcinogen exposure. The variation in tasks that they undertake results in exposure to a wide variety of different carcinogens that require similarly varied control measures.

Tobacco smoking and survival after a prostate cancer diagnosis: A systematic review and meta-analysis

BACKGROUND

While a number of studies indicate tobacco smoking has a detrimental impact on survival and recurrence after a prostate cancer diagnosis, there has been no quantitative review of this literature and it is unclear whether tobacco smoking affects clinical populations differentially. We conducted a systematic review and meta-analysis to investigate the associations between tobacco smoking and overall (OM) and prostate cancer-specific (PSM) mortality and recurrence after a prostate cancer diagnosis.

METHODS

EMBASE and ISI Web of Science were searched for English-language studies, published up to August 17, 2017, which conducted a survival analysis to estimate the association between tobacco smoking and OM, PSM and/or recurrence. A random-effects meta-analysis was conducted to estimate the summary hazard ratios (HRs) for the associations between tobacco smoking and the three outcomes.

RESULTS

A total of 28 studies met the inclusion criteria. The results of the primary meta-analysis indicate current smokers have significantly poorer overall survival (Summary HR = 1.96, 95% CI = 1.69, 2.28), prostate cancer-specific survival (Summary HR = 1.79, 95% CI = 1.47, 2.20) and recurrence-free survival (Summary HR = 1.48, 95% CI = 1.28, 1.72) than never smokers. Similar results were found in population-based studies and in studies conducted in specific clinical populations.

CONCLUSIONS

The results of this systematic review and meta-analysis indicate that tobacco smoking at prostate cancer diagnosis is associated with a significantly increased risk of overall mortality, prostate-cancer specific mortality and recurrence. We recommend future studies collect more detailed information about tobacco smoking to further understanding of the association between tobacco smoking and PCa prognosis. In addition, further research should concentrate on the impact of smoking cessation post-diagnosis and post-treatment on prognosis, and the feasibility and effectiveness of smoking cessation programs.

Isocyanates in Australia: Current exposure to an old hazard

Exposure to isocyanates has consistently been reported as the most common cause of occupational asthma. The objectives of this study were to assess how many Australian workers are currently exposed to isocyanates, identify the occupations with highest proportion of exposed workers and identify the main circumstances of exposures. Data comes from the Australian Workplace Exposure Study-Asthma, a national telephone survey which explored the prevalence of current occupational exposure to 227 asthmagens, grouped into 27 groups, among current Australian workers aged 18-65 years. A web-based tool, OccIDEAS, was used to collect job task information and to assign exposure to asthmagens, including isocyanates. Of the 4,878 eligible participants, 2.5% of them were deemed to be probably exposed to isocyanates at work in their current job (extrapolated to 3.0% of the Australian working population). The majority of those exposed were males (90.8%). The most common tasks undertaken that led to these exposures were using expanding foam fillers/sprays and isocyanate and/or polyurethane paints. Exposure occurred mainly among construction workers, wood workers, and painters or printers. This study investigating occupational exposure to isocyanates in a national working population provides information that can be used to inform the direction of occupational interventions and policies to decrease occupational asthma.

Prevalence of occupational exposure to asthmagens derived from animals, fish and/or shellfish among Australian workers

OBJECTIVE

Several animal, fish and/or shellfish derived substances encountered in the workplace can initiate or exacerbate asthma. The aims of this study were: to produce a population-based estimate of the current prevalence of occupational exposure to animal, fish and/or shellfish derived asthmagens, to identify the main circumstances of exposures and to identify occupations with the highest proportions of exposed respondents.

METHODS

We used data from the Australian Work Exposure Study-Asthma, a national telephone survey that investigated the current prevalence of occupational exposure to asthmagens among Australian workers. A web-based tool was used to collect job task information and assign exposure to asthmagens, including animal, fish and/or shellfish derived asthmagens. Prevalence ratios to determine risk factors for exposure were estimated using modified Poisson regression.

RESULTS

Of the 4878 respondents, 12.4% were exposed to asthmagens derived from animals, fish and/or shellfish. Exposure to these asthmagens was significantly higher in workers residing in regional and remote areas, compared with major cities. The main circumstance of exposure to animal derived asthmagens was through cleaning up rat/mice infestations, while the main circumstance of exposure to fish and/or shellfish derived asthmagens was through preparing and cooking salmon. Occupational groups with the highest proportion of exposure to animal or fish and/or shellfish derived asthmagens were farmers/animal workers and food workers, respectively.

CONCLUSIONS

This is the first study investigating occupational exposure to animal, fish and/or shellfish derived asthmagens in a nationwide working population. The results of this study can be used to inform the direction of occupational interventions and policies to reduce work-related asthma.

The estimated prevalence of exposure to asthmagens in the Australian workforce, 2014

Background

There is very little information available on a national level as to the number of people exposed to specific asthmagens in workplaces.

Methods

We conducted a national telephone survey in Australia to investigate the prevalence of current occupational exposure to 277 asthmagens, assembled into 27 groups. Demographic and current job information were obtained. A web-based tool, OccIDEAS, was used to collect job task information and assign exposure to each asthmagen group.

Results

In the Australian Workplace Exposure Study – Asthma (AWES- Asthma) we interviewed 4878 participants (2441 male and 2437 female). Exposure to at least one asthmagen was more common among men (47 %) than women (40 %). Extrapolated to the Australian population, approximately 2.8 million men and 1.7 million women were estimated to be exposed. Among men, the most common exposures were bioaerosols (29 %) and metals (27 %), whilst the most common exposures among women were latex (25 %) and industrial cleaning and sterilising agents (20 %).

Conclusions

This study provides information about the prevalence of exposure to asthmagens in Australian workplaces which will be useful in setting priorities for control and prevention of occupational asthma.

Electronic supplementary material

The online version of this article (doi:10.1186/s12890-016-0212-6) contains supplementary material, which is available to authorized users.

Occupational exposure to carcinogens in Australian road transport workers

BACKGROUND

Road transport workers (RTWs) are at high risk of exposure to several occupational carcinogens. However, there are gaps in knowledge regarding the extent and the circumstances of exposure. As a sub-study of the Australian Work Exposures Study, this study investigated the prevalence of occupational exposure in Australian RTWs.

METHODS

A random sample of Australian working population was invited to a telephone interview regarding their current jobs. An automated expert-assessment procedure was applied to self-reported job-related tasks using a web-based application. 162 RTWs were included in this study.

RESULTS

RTWs were exposed to diesel exhaust (97%), solar ultraviolet radiation (78%), environmental tobacco smoke (55%), benzene (29%), silica (15%), and asbestos (10%) at work. Besides driving on roads, vehicle maintenance-related tasks were the major source of carcinogen exposures among RTWs.

DISCUSSION

Most RTWs are exposed to at least one carcinogen at work. We have identified tasks where the use of control measures could potentially reduce exposures.