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Health Effects: Diesel Exhaust. Maureen Edwards, MD, MPH Center for Maternal & Child Health MD Dept. Health & Mental Hygiene Medwards@dhmh.state.md.us. Diesel Exhaust. Complex mixture of gases and fine particles
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Health Effects: Diesel Exhaust Maureen Edwards, MD, MPH Center for Maternal & Child Health MD Dept. Health & Mental Hygiene Medwards@dhmh.state.md.us
Diesel Exhaust • Complex mixture of gases and fine particles • Gaseous fraction---nitrogen, oxygen, carbon dioxide, water vapor & air pollutants, such as: carbon monoxide, sulfur oxides, nitrogen oxides, volatile organics, alkenes, aromatic hydrocarbons, and aldehydes • Ultrafine particles with chemicals adsorbed
Health Concerns Diesel Exhaust:Acute or Short-Term Exposure • Acute irritation • Eye, throat, bronchials • Neurophysiological • Lightheadedness, nausea • lung function & respiratory symptoms • Cough, mucus, labored breathing, chest tightness, wheezing
Health Concerns Diesel Exhaust/Particulates:Chronic or Long-Term Exposure • Likely carcinogenic (lungs), primarily occupational exposures • Noncancer respiratory effects • Lung inflammation and cell changes • Cough, mucus, chronic bronchitis • Immunologic reactions with increase response to allergens • Initiation asthma, asthma “attacks,” increased allergic symptoms
Relation diesel exposure & ill health? • Length of exposure • Specific component of diesel exhaust • Sensitivity of individual
Special risks to children: • Children breathe more rapidly • More often breathe through mouth • More time outdoors • Closer to ground • Have smaller airways • Have immature lungs • Therefore, at greater risk from exposures in the air
InfantAdult Respiratory volume 10 10 (ml/kg/breath) Respiration rate 40 15 (breaths/min) Minute ventilation 400150 (ml/kg/min) Breathing rates
Asthma • Chronic respiratory disease with inflammation of the airways. Bronchial hyper-responsiveness and episodic reversible airway obstruction. • Genetic & environmental factors contribute to its development. • Indoor & outdoor triggers lead to “attacks.” • Controlled by avoidance of triggers & regular medication.
Asthma: Maryland Children • 11 % or >150,000 have a history of asthma • >14,000 emergency department visits 2002 • >2500 hospitalizations 2002 • 7 children died (2003), 2 (2002)
Children’s diesel exposure • Bus: • Age of bus, type of fuel, filters • Bus ride: • Time on bus, idling, open/closed windows, airflow, back/front of bus • Other exposures to combustion products
Children’s Environmental Health Protection • Limit exposure to all potential toxins • Concern for most sensitive population • Children, persons with asthma • Invoke the “precautionary principle” • Extra factor for safety if exposure not proven safe