Identifying and managing adverse environmental health effects: 2. Outdoor air pollution

AIR POLLUTION CONTRIBUTES TO PREVENTABLE ILLNESS AND DEATH. Subgroups of patients who appear to be more sensitive to the effects of air pollution include young children, the elderly and people with existing chronic cardiac and respiratory disease such as chronic obstructive pulmonary disease and asthma. It is unclear whether air pollution contributes to the development of asthma, but it does trigger asthma episodes. Physicians are in a position to identify patients at particular risk of health effects from air pollution exposure and to suggest timely and appropriate actions that these patients can take to protect themselves. A simple tool that uses the CH²OPD² mnemonic (Community, Home, Hobbies, Occupation, Personal habits, Diet and Drugs) can help physicians take patients'' environmental exposure histories to assess those who may be at risk. As public health advocates, physicians contribute to the primary prevention of illness and death related to air pollution in the population. In this article we review the origins of air pollutants, the pathophysiology of health effects, the burden of illness and the clinical implications of smog exposure using the illustrative case of an adolescent patient with asthma.Case A 16-year-old girl and her mother visit their family physician in July because the daughter woke up at 6 am that morning with shortness of breath, a cough and tightness in her chest. The girl has a history of asthma and used salbutamol soon after the onset of symptoms, with some but not total relief. She reports having had no symptoms during the previous month. She had a few episodes of wheezing the previous summer, which resolved with the use of salbutamol, and a cough that persisted for 2 weeks after an upper respiratory tract infection in the winter. She has no history of allergies, hayfever or other medical problems. She is a nonsmoker and has no family history of allergies. Audible wheezing is detected on physical examination, but the girl does not appear to be in distress. Her vital signs are normal, as are the results of the ear-nose-throat and cardiovascular examinations. Respiratory examination reveals wheezing throughout chest, no focal findings and a centrally placed trachea. The girl''s calves are soft and nontender, and there is no evidence of ankle edema. Her peak expiratory flow is 240 L/min (expected for height 400 L/min). Spirometry testing is unavailable. Fifteen minutes after 2 puffs of salbutamol her peak expiratory flow increases to 320 L/min. To identify possible exposures that may have contributed to the asthma episode, the physician quickly takes an environmental exposure history using the CH²OPD² mnemonic — Community, Home, Hobbies, Occupation, Personal habits, Drugs and Diet (1Table 1Open in a separate windowQuestions surrounding this case: What was the patient''s exposure to outdoor air pollutants? How should the patient and family be counselled about dealing with these trigger factors? What are the possible inducers and triggers from indoor air pollution? How can the patient and family find out about the status of outdoor air quality in their community?