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Abstract Necrophagous flies are of great importance for human and animal health. In places where their development occurs, parasitoids can be used as a tool to control these dipterans. In Brazil, the fauna of these parasitoids has been investigated in some regions. However, in Rio Grande do Sul, it is known the occurrence of only one species. Thus, this study aimed to create the first list of parasitoids in flies of medical and veterinary importance in Southern Brazil. Collections took place in the municipality of Pelotas (31º 42’ S; 52º 18’ W). Three replicates consisting of a 500 g bovine liver chunk placed in a tray were exposed to open air for 20 days. Then pupae were individualized and observed until their emergence. We identified 4,882 adult flies of Calliphoridae, Fanniidae, Muscidae, and Sarcophagidae. 4,040 parasitoids emerged, belonging to eight species, of which Nasonia vitripennis, Spalangia cameroni, Spalangia chontalensis, and Tachinephagus zealandicus are new records in Rio Grande do Sul state. Also, three undescribed species of the genus Aphaereta were collected. In spite of being the first attempt to inventory the fauna of hymenopteran parasitoids, this study may help in the development of management programs of these dipterans in the region.

This second of two parts continues with the development of a framework for understanding air quality issues and their relationship to human health. Recognized health effects associated with air pollution are described and current controversies regarding ozone and PM10 are briefly outlined. Epidemiological methods of investigating air quality effects are discussed, comparing recent landmark studies in Canada. Comparative prevalence studies do not reflect the state of the art in air pollution epidemiology but are frequently cited and conducted in Canada as if they were definitive. The implications of setting air quality standards and objectives on this basis or to meet arbitrary levels of risk of health effects are examined. The current state of the art does not support risk-based air quality standards. A policy of continuous improvement is most protective of both human health and the environment.

There is a fundamental reevaluation of the association between air quality and human health taking place. This reevaluation is motivated by several recent developments: increasing interest in air quality as an environmental issue; interest in the unanswered questions regarding the epidemiology of asthma; and the reduced prevalence of the principal hazard to respiratory health, cigarette smoking, the control of which invites interest in second-order determinants of health. This article attempts to provide a framework for understanding air quality issues that pertain to human health. The objective is to provide the specialist in respiratory medicine with an overview that will assist in educating patients and in responding to their inquiries, and to equip the physician to respond to requests for assistance or interpretation when called upon to comment on public policy issues involving air pollution. The implications of setting air quality standards or objectives to meet arbitrary levels of risk of health effects are examined. The current state of the art does not support risk-based air quality standards. A policy of continuous improvement is most protective of both human health and the environment.

Trends in mortality from chronic obstructive pulmonary disease (COPD) in Alberta over 60 years, from 1927 to 1987, for ages 15 and above or both sexes, were examined. There was a striking decline in mortality among older adults in the 1930s and 1940s. a nadir that lasted almost 10 years in the 1950s, and a striking increase thereafter. By 1970, most age groups had returned to levels of the 1930s. This overall trend was observed in both the younger age groups (aged 15 to 50) and older adults, although mortality from COPD in the former disproportionately reflected asthma-related deaths. Subsequently, mortality climbed still higher in older age groups, but not in the younger age groups. The sustained rise in mortality in older age groups after the Second World War is presumably related to smoking habits. Historical trends in Alberta were then compared with Canada as a whole for both sexes over 50 years of age. Although Alberta had a much lower mortality from COPD than Canada as a whole, this difference disappeared by 1980. There is no obvious explanation that would explain all of the observed trends, but they appear more likely to be a consequence of social and environmental conditions, including changes in health-related behaviour, than of major changes in medical management at the time.