Can Fam Physician. 1971 Nov;17(11):39-44.
The author reviews possible relationships between chronic bronchitis and air pollution, drawing attention to the difference in incidence of chronic bronchitis between England and Canada, and the recent increase in mortality from respiratory diseases in Canada.Neither air pollution nor smoking habits can fully account for these phenomena. Dr. Shephard describes methods of measuring pollution and concludes that Toronto is intrinsically as dirty as other cities of comparable size, and that although there have been substantial decreases of smoke over the past decade, levels of gaseous acid have shown little improvement. Urban/rural comparisons suggest that high concentrations of pollutants can double the prevalence of chronic bronchitis; however, the effect is much less obvious if comparisons are restricted to non-smokers of comparable social status. Longitudinal surveys suggest a worsening of condition in bronchitics during periods of intense pollution. Justification for air pollution control programs lies more in the prevention of damage to buildings and beauty then in a specific effect upon human health.
作者回顾了慢性支气管炎与空气污染之间可能存在的关系，提请注意英格兰和加拿大之间慢性支气管炎发病率的差异，以及加拿大呼吸系统疾病死亡率的近期上升。空气污染和吸烟习惯都不能完全解释这些现象。谢泼德博士描述了测量污染的方法，并得出结论，多伦多本质上和其他同等规模的城市一样脏，尽管在过去十年中，烟尘排放量大幅下降，但气态酸的水平几乎没有改善。城市与农村的比较表明，污染物的高浓度会使慢性支气管炎的患病率增加一倍；然而，如果仅限于比较社会地位相当的不吸烟者，这种影响就不那么明显了。纵向调查表明，在污染严重期间，慢性支气管炎患者的病情恶化。空气污染控制计划的理由更多地在于防止建筑物和美观受损，而不是对人类健康产生特定影响。
