Primary prevention of occupational asthma B. Nemery Occupational, Environmental & Insurance Medicine & Pneumology K.U.Leuven

Risk management Hazard evaluation (toxicity) Exposure evaluation Risk assessment Risk management

Primary prevention ? Improve risk assessment Risk evaluation Exposure evaluation  Epidemiology  Experimental research

Experimental research develop good & robust animal models of (occupational) asthma Predictive toxicology: identification of «asthmogens» high molecular weight agents low molecular weight agents  Primary sensitization potential (potent – weak)  Ability to cause relevant respiratory responses in sensitized subjects

Experimental research develop good & robust animal models of (occupational) asthma Mechanistic toxicology: understanding mechanisms of sensitization (dermal / mucosal; antigen presentation; dose - response relationships; threshold - tolerance; role of irritants; genetics;...) respiratory responses to sensitization (bronchoconstriction, lung inflammation, airway remodelling; resolution / persistence; role of irritants; genetics,...)

Practical consequences Experimental research should improve hazard assessment hazard identification  «complete» vs «incomplete» asthmogens  «adjuvants», «co-asthmogens» & «promoters» hazard characterization  dose-response relationships  thresholds of exposure ? susceptibility factors & protective factors  genetic susceptibility  co-exposures & other determinants

Practical consequences Improved risk assessment → better risk management (i.e. primary prevention) prevent/regulate exposure to sensitizers & asthmogens based on scientific evidence  does inhalation of a dermal sensitizer represent a risk of occupational asthma (labelling) ?  to prevent (some forms of) occupational asthma, it may be more useful to prevent skin contact, than to wear masks

Risk management Hazard evaluation (toxicity) Exposure evaluation Risk assessment Risk management Cost-benefit analysisRisk perception

Primary prevention ? Improve risk assessment Strenghten risk management  Psycho-sociological research

Primary prevention? Psycho-sociological (behavioural) research: Awareness of risk ? Intention to adopt preventive behaviour ? by decision makers by industry and employers by workers

Behavioural research D. Piette & Y. Coppieters (U. L. Brussels) Research project to assess awareness of risks of occupational disease understand determinants of intentions to adopt preventive behaviour at work in young people at high risk of occupational asthma bakers, hairdressers, woodworkers at low risk of occupational asthma butchers, shop assistants  cross-sectional baseline study at the end of education  longitudinal follow-up after 2 years (on the job)

Baseline study Coppieters Y., Piette D. Targeting pupils at risk of occupational asthma. Patient Education and Counseling, 2004, in press (doi: /j.pec ) doi: /j.pec /587 final year students (45 classes, 15 schools) bakers (n=235), hairdressers (n=93), woodworkers (n=59), butchers (n=56), shop assistants (n=90) self-administered questionnaire demographics, family structure, socioeconomic status beliefs & behaviour re occupational risk (incl. occ. asthma) perceived risk (perceived seriousness & susceptibility, benefits of prevention) intention to adopt preventive behaviour (attitude, perceived norms) & perceived behavioural control respiratory symptoms in past 6 months, incl. asthma

Baseline study 1. awareness of occupational risks in future job 2. awareness of risk of occupational asthma bakers61%24% hairdressers54%15% woodworkers79% 5% butchers66% 2% shop assistants44% 2% low degree of risk perception low intention to adopt preventive behaviour boys < girls, not influenced by smoking etc. somewhat higher awareness if father has manual job (but then also less feeling of control over risk)

Baseline study asthmawheezing bakers12.6% 21.4% hairdressers14.1% 26.7% woodworkers 3.5% 8.6% butchers 9.3% 16.5% shop assistants 7.4% 9.5%

Follow-up study (2 y) Coppieters Y., Nemery B., Piette D. (in preparation) same questionnaire after 1 and 2 y n = 223 at 2 y bakers (n=117), hairdressers (n=31), woodworkers (n=28), butchers (n=20), shop assistants (n=27) in high risk jobs: higher risk of reporting respiratory symptoms if symptomatic at baseline (OR 2.3 to 3.4), smoker (OR 1.6), foreign (OR 1.7) low initial perception of risk increases slightly (increased perceived seriousness & susceptibility) low initial intention to adopt preventive behaviour improves somewhat (increased confidence that it is feasible to adopt preventive measures)  important role of education (norms)

Risk management Hazard evaluation (toxicity) Exposure evaluation Risk assessment Risk management Cost-benefit analysisRisk perception