Induction of Asthma and the Environment: What We Know and Need to Know

Abstract

The prevalence of asthma has increased dramatically over the last 25 years in the United States and in other nations as a result of ill-defined changes in living conditions in modern society. On 18 and 19 October 2004 the U.S. Environmental Protection Agency and the National Institute of Environmental Health Sciences sponsored the workshop “Environmental Influences on the Induction and Incidence of Asthma” to review current scientific evidence with respect to factors that may contribute to the induction of asthma. Participants addressed two broad questions: a) What does the science suggest that regulatory and public health agencies could do now to reduce the incidence of asthma? and b) What research is needed to improve our understanding of the factors that contribute to the induction of asthma and our ability to manage this problem? In this article (one of four articles resulting from the workshop), we briefly characterize asthma and its public health and economic impacts, and intervention strategies that have been successfully used to prevent induction of asthma in the workplace. We conclude with the findings of seven working groups that focus on ambient air, indoor pollutants (biologics), occupational exposures, early life stages, older adults, intrinsic susceptibility, and lifestyle. These groups found strong scientific support for public health efforts to limit in utero and postnatal exposure to cigarette smoke. However, with respect to other potential types of interventions, participants noted many scientific questions, which are summarized in this article. Research to address these questions could have a significant public health and economic impact that would be well worth the investment.

Indoor airborne fungi and wheeze in the first year of life among a cohort of infants at risk for asthma

“…Evidence suggests that the development of asthma occurs primarily during early childhood and involves both genetic and environmental factors including biologics (e.g., allergens, viruses, bacterial products). The timing and ''dose'' of the environmental exposures and the interaction with genes and other susceptibility factors (e.g., breast-feeding, lifestyle) during specific developmental periods appear critical to the induction of asthma (Martinez, 2003;Yeatts et al, 2006;Gilmour et al, 2006;Zeldin et al, 2006;Selgrade et al, 2006). It is likely that fungal allergens eliciting immunological and airway changes during this critical developmental period are dependent in part, on the geographic area and climate (Martinez, 2002), perhaps accounting for the variety of fungal taxa-respiratory symptom associations which have been observed.…”

Exposure to phthalates: Reproductive outcome and children health. A review of epidemiological studies

“…Because of the rapid character of this phenomenon, it is believed to be caused by changes in environmental exposures rather than genetic changes [75]. There is accumulating scientific data supporting the hypothesis that exposure to phthalates from DIBP -diisobutyl phthalate; DnBP -di-n-butyl phthalate; BBzP -n-butylbenzyl; DINP -diisononyl phthalate; DnOP -di-n-octyl phthalate.…”

Exposure to Traffic-related Particles and Endotoxin during Infancy Is Associated with Wheezing at Age 3 Years

“…It has been hypothesized that failure of the immune system to modify or suppress Th2-biased cellular cytokine responses can lead to development of atopic clinical phenotypes, including allergic rhinitis and asthma. Thus, there may be periods of life, particularly in the first year, when air pollutants, indoor endotoxin, pets, and aeroallergen exposures may either modify or enhance development of allergic disorders in childhood (26).…”