New Directions - New Dimensions for Environmental Health Research in Canada

by John D. Eyles | Oct 01, 1999

Executive Summary

The environment shapes the health of all Canadians by contributing to our burden of illness and improving our health and sense of well-being. The results of past research and practice have demonstrated the relationships between environment and health and these relationships have been recognized in the Determinants of Health model widely adopted in Canada and abroad. Environment is a vital determinant not only in terms of physical but also psycho-social health. It is framed by risk and hazard in that as a determinant of health its effects are seen as hazards while its outcomes for humans are framed as risks. It is thus a determinant of real consequence in modern society or as Beck (1992) puts it, the “risk society.”

The federal, provincial, and territorial ministers of health view environment as one of the defining characteristics of health, with environment defined as physical, chemical, biological and organizational factors in the environment whether it be natural, humanbuilt or the workplace (1994). Shah, in his major review of public health and preventative medicine in Canada (1998), isolates three sets of factors as determinants of health and disease: human biology, environment (including physical and social environments) and lifestyle/behaviour. Health Canada specifically highlighted these relationships in such documents as Health and Environment: Partners for Life (1997), and specified “identifying and reducing health risks from the environment” as one of four strategic themes for its action plan in Sustaining Our Health (1997). Internationally, the World Health Organization is promoting action based on the relationship, for example, in Health and Environment in Sustainable Development - Five Years after the Earth Summit. In virtually all frameworks developed to help understand what determines health and sickness, environment is noted as a significant factor.

Research supports the relationships between environment and health outcomes but also reveals these relationships to be increasingly complex. The environment itself is a complex entity and often poorly defined, yet it is the milieu in which all human activity occurs. The air we breathe, the water we drink, the soils we till, and the food we eat are all potentially compromised by human activities that affect the physical environment. There is national concern that the natural environments and unique ecosystems of Canada are being compromised by human activity: for example, the Arctic ecosystem is at risk because of human activities far removed from the Arctic (e.g., long-range transport of pollutants, global warming, changes in the ozone layer) and consequently, Aboriginal health and sustainability of traditional practices are threatened. The Great Lakes ecosystem is home to over 50 percent of Canadian investment and economic activity; deteriorating water quality and particularly air quality now threaten the public’s health in the region, a situation recognized by public health associations and medical organizations alike.

Health can be seen as complete physical, psychological and social well-being and as a resource for living. Hence, it can either be enhanced or compromised by one’s physical, psychological and social environments. Where we live can provide a refuge and a haven and improve our mental health. Yet psycho-social health can be adversely affected by living close to a noxious waste facility or a polluting industry. Studies have shown not only high levels of concern, anxiety and community action, but also elevated rates of self-reported physical distress and illness in such communities. Further, the anticipation of being affected by a compromised environment can have an adverse impact on physical and mental functioning.

It is not only the immediate environment that has the potential for impacts on health. Global climate change will likely have associated illnesses and deaths from more frequent heat and extreme-weather events. A rising incidence of infection and disease is expected to accompany climate induced ecosystem change. Some forms of technological hazard may also increase with climate change: for example, photochemical pollutants (e.g., smog) are likely to rise with higher ambient temperatures so respiratory illness may also increase. Indirect effects of global climate change may involve threats to food and water security and increased stress on publichealth infrastructure.

The specific linkages between environment and health often remain tentative and uncertain. This applies especially around emerging concerns such as threats to the supply and quality of food. For example, the linkages between agricultural practices, animal husbandry, zoonoses and human diseases such as Creutzfeldt-Jakob disease have only recently been appreciated. Other uncertainties arise because of apparently contradictory evidence about the same environmental health relationship produced in different studies often utilizing different methodologies and outcomes of interest. The recent British Columbia and Ontario studies on the association between childhood leukemia and electric-magnetic field exposure offer a good example of this. This lack of research consensus on so many topics of public and policy interest has produced significant public concern about the effects of the environment on people’s health.

Not only is there often lack of research consensus but the environment itself contains many of the features that produce fear and anxiety. Unlike virtually all the other determinants of health, the environment is not controlled by individuals or by mandated programs. Environment is where involuntary exposure to risk and hazard occur. Harmful exposures are often caused by distant activities in which exposed individuals have not directly participated. This lack of control in assigning blame or negligence can further contribute to anxiety. Further, our lifestyles increasingly detach us from the environment so we lack personal experience of potential hazards, hence intensifying our fear of the unknown.

In recognition that:

  1. environment is a key determinant of health,
  2. the relationships between environment and health are extremely complex,
  3. the factors mediating these relationships are very diverse,
  4. there are great uncertainties and public concerns about the environment and its impact on health, and
  5. there is so little known about many environmental health issues,

We propose a more intensive and integrated commitment to research into environment and health be made. An integrated and intensive approach that links scientists from many different disciplines will greatly increase the probabilities of transformational breakthroughs and innovative insights in this complex multi-dimensional area of health. Quick progress could be made through creating a Canadian Institute of Environmental Health Research (CIEHR) that encompasses all four cross-cutting themes of enquiry:

  • Basic biomedical research aims at understanding biological, physiological, anatomical, biochemical, genetic and behavioural phenomena which operate at individual, organ, cell, and molecular levels. For environmental health research, the identification of toxic and infectious elements in the environment and their effect on body function and health are key. Toxicology and genetics have significant roles to play as does epidemiology to identify the determinants and distributions of the exposures and outcomes of interest in particular populations.
  • Applied clinical research is concerned with the application of knowledge for effective clinical interventions. For environmental health, it is important, too, to identify and assess public health interventions for determining the effectiveness, efficiency and efficacy of a different program, practice or policy. Evaluation and outcomes research combine with the basic biomedical to assess evidence and the procedures derived therefrom. “Evidence-based practice” links the applied clinical to the policy domain.
  • Society, culture and population health research focuses on making discoveries in understanding the determinants of health in populations and how social systems affect health. A CIEHR would also be firmly located in this research sector, establishing the relationships between environmental quality, exposure and different health outcomes in studies to identify the environmental burden of illness, environmental effects in relation to those of other determinants, and environment as an enhancer of quality of life. Epidemiological and quantitative social research are important tools as are qualitative methods and ways of addressing issues of justice and fairness in the ecologic and socio-geographical distributions of environmental exposures and health outcomes.
  • Health services and systems research relates to those systems and policies which affect health, including the delivery of services and activities in non-health sectors. Environmental health research will focus on understanding and explaining the formulation and implementation of systems, structures and policies. By their nature, such phenomena are multi-sectoral and will require that attention be given to health, environment, natural resources, law, economic development, recreation and tourism, finance and so on. Policy science and database development are major tools in this sector.

Biomedical and applied clinical approaches to health are well-suited to provide answers to the crucial what question of environment and health relationships, whereas the social sciences and humanities help address the who, when, where, and why questions. The how questions about individual and community coping responses and the policy response bring in the health services/systems researchers as well as the social scientists and humanists.

Environmental health research demands an integrated approach. Through a CIEHR, knowledge will be generated with some or all of the four cross-cutting themes, depending on the questions, problems or issues at hand. It will bring disciplines together and apply the appropriate cross-cutting methodologies to the research tasks. Its research will be both cross-disciplinary and cross-sectoral, being better able to answer the questions that concern Canadians about the relationships between environment and health.