A review of the medical evidence for a link between air pollution and asthma

Recently the possible link between air pollution and asthma has been at the centre of much political, public and media attention. This concern has been fuelled by evidence of increasing respiratory ill health, especially in children, and the search for an explanation has focused upon environmental pollution, particularly emissions from road transport. Paradoxically this concern has not been induced by new findings that address the fundamental question of the importance of current levels of air pollution in the causation, severity and responses in asthma. Asthma is predominantly an allergic disease of the human airways. These airways are known to become inflamed in response to exposure to a host of environmental factors. This paper reviews evidence of a link between pollution and asthma and examines the role of pollution in the expression of asthma. In more than 90 percent of children in the UK with asthma the major allergen is a protein particle secreted by house dust mites and this is likely to be the cause of the disease in most sufferers. However, if air pollution has a role it must be expressed in one of three ways. First, certain pollutants acting together, singly, or with other environmental triggers, may cause changes in airways and cause symptoms in people already suffering from asthma. Secondly, air pollution may be causing the initiation of asthma by a mechanism independent of other factors. Thirdly, exposure to pollutants may act in combination with allergens to initiate the asthmatic tendency. The medical evidence for each of these possible roles will be discussed. It is crucial that answers are forthcoming to these questions in order that effective and timely air pollution control strategies may be introduced.This paper was delivered at the Global Forum '94 Academic Conference.     

LAKE LOADING RATIOS (N:P) AND LACUSTRINE NITROGEN FiXATION?

ABSTRACT: Data from seven diverse lakes with reasonably complete nutrient budgets and estimates of annual areal nitrogen fixation (AANF) were used to evaluate the proposition that nitrogen fixation (NF) declines as the ratio TN:TP in lake loadings increases. The results do not support the conclusion that the rate of AANF in lakes is related to the N:P ratio in externally generated influents, although low N:P nutrient loading ratios often favor blue-green algae capable of NF.     

Particulate matter emissions during autopsies: a method to reduce exposure

Environmental Science and Pollution Research - Particulate matter emitted during autopsies can serve as a vector for numerous viruses or bacteria and can lead to infections. Reducing the exposure...