Occupational risk factors and exposure-response relationships for airway disease among health workers exposed to cleaning agents in tertiary hospitals.

OBJECTIVES: This study investigated occupational risk factors and exposure-response relationships for airway disease among health workers (HWs) exposed to cleaning agents in two tertiary hospitals in South Africa and Tanzania. METHODS: In this cross-sectional study, 697 participants completed questionnaire interviews while 654 underwent fractional exhaled nitric oxide (FeNO) testing. Asthma Symptom Score (ASS) was computed based on the sum of answers to five questions on asthma-related symptoms in the past 12 months. For exposure-response analyses, cleaning agent-related self-reported exposure variables were categorised into three levels (cleaning product not used; use of a cleaning product for up to 99 min per week and use of a cleaning product for ≥100 min per week). RESULTS: Asthma-related outcomes (ASS and FeNO) demonstrated positive associations with medical instrument cleaning agents (orthophthalaldehyde and enzymatic cleaners) and tasks (instruments precleaning and changing sterilisation solutions) as well as patient care activities (disinfection prior to procedures and disinfecting wounds). A particularly pronounced dose-response relationship was observed between work-related ocular-nasal symptoms and medical instrument cleaning agents (orthophthalaldehyde, glutaraldehyde, enzymatic cleaners, alcohols and bleach) (OR range: 2.37-4.56) and tasks (OR range: 2.92-4.44). A strong association was also observed between ASS and use of sprays for fixed surface cleaning (mean ratio 2.81; 95% CI 1.41 to 5.59). CONCLUSIONS: Specific agents for medical instrument disinfection for example, orthophthalaldehyde and enzymatic cleaners, patient care activities and use of sprays are important occupational risk factors for airway disease among HWs.

Ensemble averaging using remote sensing data to model spatiotemporal PM10 concentrations in sparsely monitored South Africa.

There is a paucity of air quality data in sub-Saharan African countries to inform science driven air quality management and epidemiological studies. We investigated the use of available remote-sensing aerosol optical depth (AOD) data to develop spatially and temporally resolved models to predict daily particulate matter (PM10) concentrations across four provinces of South Africa (Gauteng, Mpumalanga, KwaZulu-Natal and Western Cape) for the year 2016 in a two-staged approach. In stage 1, a Random Forest (RF) model was used to impute Multiangle Implementation of Atmospheric Correction AOD data for days where it was missing. In stage 2, the machine learner algorithms RF, Gradient Boosting and Support Vector Regression were used to model the relationship between ground-monitored PM10 data, AOD and other spatial and temporal predictors. These were subsequently combined in an ensemble model to predict daily PM10 concentrations at 1 km × 1 km spatial resolution across the four provinces. An out-of-bag R2 of 0.96 was achieved for the first stage model. The stage 2 cross-validated (CV) ensemble model captured 0.84 variability in ground-monitored PM10 with a spatial CV R2 of 0.48 and temporal CV R2 of 0.80. The stage 2 model indicated an optimal performance of the daily predictions when aggregated to monthly and annual means. Our results suggest that a combination of remote sensing data, chemical transport model estimates and other spatiotemporal predictors has the potential to improve air quality exposure data in South Africa's major industrial provinces. In particular, the use of a combined ensemble approach was found to be useful for this area with limited availability of air pollution ground monitoring data.

Health-Related Quality of Life (HRQoL) of Residents with Persistent Lower Respiratory Symptoms or Asthma Following a Sulphur Stockpile Fire Incident.

Background: This study evaluated health-related quality of life (HRQoL) in residents with persistent lower respiratory symptoms (PLRS) or asthma six years after exposure to sulphur dioxide vapours emanating from an ignited sulphur stockpile. Methods: A cross-sectional study was carried out, using interview data collected at three time points (prior to, one- and six-years post incident), medical history, respiratory symptoms and HRQOL using the Medical Outcomes Study Form 36 (SF-36). Results: A total of 246 records, 74 with and 172 without PLRS or asthma, were analysed. The mean age was 42 (SD:12) years in the symptomatic group and 41 (SD:13) years in the asymptomatic group. Mean SF-36 scores were significantly lower for the symptomatic group in the Physical Functioning (24 vs. 39), Role-Physical (33 vs. 48) and General Health (GH) domains (24 vs. 37). Symptomatic residents experienced a significant decline in their Role-Physical (OR = 1.97; CI 1.09, 3.55) and GH (OR = 3.50; CI 1.39, 8.79) at year 6 compared to asymptomatic participants. Residents with co-morbid reactive upper airways dysfunction syndrome demonstrated stronger associations for GH (OR = 7.04; CI 1.61, 30.7) at year 1 and at year 6 (OR = 8.58; CI 1.10, 65.02). Conclusions: This study highlights the long-term adverse impact on HRQoL among residents with PLRS or asthma following a sulphur stockpile fire disaster.

The neglected millions: the global state of aquaculture workers' occupational safety, health and well-being.

A scoping project was funded by the Food and Agriculture Organization in 2017 on the health and safety of aquaculture workers. This project developed a template covering basic types of aquaculture production, health and safety hazards and risks, and related data on injuries and occupational ill health, regulations, social welfare conditions, and labour and industry activity in the sector. Profiles using the template were then produced for key aquaculture regions and nations across the globe where information could be obtained. These revealed both the scale and depth of occupational safety and health (OSH) challenges in terms of data gaps, a lack of or poor risk assessment and management, inadequate monitoring and regulation, and limited information generally about aquaculture OSH. Risks are especially high for offshore/marine aquaculture workers. Good practice as well as barriers to improving aquaculture OSH were noted. The findings from the profiles were brought together in an analysis of current knowledge on injury and work-related ill health, standards and regulation, non-work socioeconomic factors affecting aquaculture OSH, and the role of labour and industry in dealing with aquaculture OSH challenges. Some examples of governmental and labour, industry and non-governmental organisation good practice were identified. Some databases on injury and disease in the sector and research initiatives that solved problems were noted. However, there are many challenges especially in rural and remote areas across Asia but also in the northern hemisphere that need to be addressed. Action now is possible based on the knowledge available, with further research an important but secondary objective.

Work-related allergic respiratory disease and asthma in spice mill workers is associated with inhalant chili pepper and garlic exposures.

OBJECTIVE: The aim of the study was to determine the prevalence and risk factors for allergic respiratory disease in spice mill workers. METHODS: A cross-sectional study of 150 workers used European Community Respiratory Health Survey questionnaires, Phadiatop, serum specific IgE (garlic, chili pepper), spirometry and fractional exhaled nitric oxide (FeNO). Personal air samples (n=62) collected from eight-hour shifts were analysed for inhalable particulate mass. Novel immunological assays quantified airborne garlic and chili pepper allergen concentrations. RESULTS: Mean dust particulate mass (geometric mean (GM)=2.06 mg/m(3)), chili pepper (GM=0.44 µg/m(3)) and garlic allergen (GM=0.24 µg/m(3)) were highest in blending and were highly correlated. Workers' mean age was 33 years, 71% were men, 46% current smokers and 45% atopic. Spice-dust-related asthma-like symptoms (17%) were common, as was garlic sensitisation (19%), with 13% being monosensitised and 6% cosensitised to chili pepper. Airflow reversibility and FeNO>50 ppb was present in 4% and 8% of workers respectively. Spice-dust-related ocular-nasal (OR 2.40, CI 1.09 to 5.27) and asthma-like (OR 4.15, CI 1.09 to 15.72) symptoms were strongly associated with airborne garlic in the highly exposed (>0.235 µg/m(3)) workers. Workers monosensitised to garlic were more likely to be exposed to higher airborne chili pepper (>0.92 µg/m(3)) (OR 11.52, CI 1.17 to 113.11) than garlic allergens (OR 5.08, CI 1.17 to 22.08) in this mill. Probable asthma was also more strongly associated with chili pepper than with garlic sensitisation. CONCLUSIONS: Exposure to inhalable spice dust (GM >2.06 mg/m(3)) containing garlic (GM>0.24 µg/m³) and chili pepper (GM >0.44 µg/m(3)) allergens increase the risk of allergic respiratory disease and asthma.

Sensitisation to cereal flour allergens is a major determinant of elevated exhaled nitric oxide in bakers.

OBJECTIVE: Various studies of the usefulness of fractional exhaled nitric oxide (FeNO) in occupational settings remain inconclusive. The objective was to investigate the determinants of increased FeNO in bakery workers. METHODS: A cross-sectional study of 424 supermarket bakery workers used a questionnaire and serum specific IgE to wheat, rye and α-amylase. FeNO during the work shift were assessed using a hand-held portable sampling device (NIOX MINO). RESULTS: The median FeNO was 15 ppb, in atopics 21 ppb and current smokers 12 ppb. Increased FeNO was strongly associated with IgE to wheat independent of smoking and atopy status. In the multivariate model, IgE to wheat, current smoking, atopy and age were significantly associated with FeNO. Stratified analysis in a subgroup of atopic non-smokers demonstrated the strongest relationship between FeNO and various clinical endpoint such as wheat (OR=9.43) or rye (OR=11.76) sensitisation, work-related allergic rhinitis (OR=8.13) or asthma (OR=5.44), and probable baker's asthma (OR=6.72). CONCLUSIONS: Sensitisation to cereal flour allergens rather than asthma symptoms is a major determinant of elevated FeNO among bakers. This relationship is modified by atopy and current smoking status.