Environmental determinants are among the greatest causes of health inequalities between and within countries. These determinants include the workplace, housing, sanitation, and air quality, among others. For many individuals globally, good health status is difficult to attain due to the hazardous environments in which they live. For example, low income neighborhoods in the United States are frequently characterized by danger, violence and lack of positive social connections. This leads to elevated stress and greater risk of stroke, poorer birth outcomes, and increased health problems relative to other environments.(1)
Traditionally, global health policy has focused on the provision and funding of medical care. Today, we understand that while medical care can improve prognosis, the social, economic, and environmental conditions in which we live are important factors in determining human health. This article discusses the characteristics of women and children that make them particularly vulnerable to environmental hazards. In addition, this article outlines the different environmental risks between wealthy and low-income countries as well as potential strategies to reduce them.
“In affluent as well as in deprived populations, the most compelling socio-medical problems have their origin in the lasting and often irreversible effects of early environmental influences.”(2)
Environmental health includes all the conditions, influences, and interactions between individuals and their environment as well as the effects of these interactions on their health. “This broad view of environmental health includes the chemical, physical, and biological risks that cause or influence diseases in women and children." (3) Thus, the field of environmental health is all-encompassing and has immense repercussions for the health of humans as well as the ecosystem.
“In the developing world, social, economic, and environmental risks combine to create a triple burden for mothers and children. Poverty, poor nutrition, environmental pressures, and displacement caused by such forces as climate change or conflict precipitate more exposure to environmental health threats.”(4)
In resource-poor settings, environmental risks stem from a variety of sources, including unclean water, poor sanitation, crowded living situations, dangerous working conditions, and smoke from biomass cooking. In developed and developing nations, health risks are created by air pollution from industry and power plants as well as chemical pollution of water. These threats form the foundation of poor health and often cause and exacerbate other diseases. For example, while tremendous progress has been made to create vaccines that prevent diarrhea, increased attention is needed to address the underlying social and environmental determinants such as clean water.
While individuals across all regions of the world are exposed to environmental hazards, children have characteristics that make them particularly vulnerable. For example, children have rapid physical and mental development and growth. These growth spurts necessitate high energy requirements that are easily compromised by under-nutrition—a lack of nutrients available due to environmental conditions. Globally, food insecurity is associated with micronutrient deficiencies, and an estimated 4.5 billion people worldwide are affected by some form of nutrient deficiency. Of this 4.5 million, the most vulnerable groups are young children and women of childbearing age. Pregnant women are particularly susceptible to environmental risks given their high nutrient requirements.
“Children also have metabolic rates; they eat more, drink more, and breathe more in relation to their body size, increasing the exposure to harmful substances when reported as a proportion to body mass. Yet, a child’s immature organs and systems lack competence to detoxify and excrete potentially hazardous compounds. Children have smaller airways, increasing the hazardous effect of agents that cause mucosal irritation and airway narrowing.” (5)
Indoor air pollution takes many forms, ranging from smoke emitted from solid fuel combustion during cooking to complex mixtures of chemicals present in modern buildings. Health risks from indoor air pollution are likely to be greatest in developing countries. In many households, everyday exposure to air pollution may contribute to an increasing prevalence of asthma, cancer, and cataract.(6)
In poverty-stricken communities, inadequate housing ventilation and improper cooking stoves pose a danger to women who do most of the food preparation. Dangerous smoke released from burning unclean solid fuel sources often has no direct path out of the house due to unflued stoves. One study found that less than 20 % of homes in poor areas of northeastern Brazil and central Mexico were safe to live and breathe in. Wood smoke contains many chemical products such carcinogens, carbon monoxide, and hydrocarbons that are detrimental to human health.(7)
Many people in the developing world are forced to use such fuels for cooking because of deforestation, population expansion, and degradation of agriculture and land. “In fact, nearly half the world's population prepares meals with wood or wood-replacement fuels on primitive stoves without chimneys.”(8) The consequences of indoor air pollution are revealed in a study conducted in Nepal and India which examined the association between cooking with unflued indoor stoves and development of cataract. This study found that the use of solid fuel in unflued indoor stoves is associated with increased risk of developing cataract in women.(9) After controlling for differences in age, educational status, type of housing, type of lighting and occupation, it was found that the use of an unflued solid-fuel stove is an independent risk factor for the development of cataract.
In order to address the dangers posed by exposure to smoke, several solutions have been suggested. First, unflued stoves can be replaced with flued stoves which greatly improve ventilation. Cooking in an unventilated kitchen doubles the risk of cataract and other diseases compared with cooking in a fully or partially ventilated kitchen. By allowing smoke to exit the house, this risk could be reduced. However, cooking with cleaner burning fuels would be the best option. Increased ventilation in the kitchen is helpful, but ventilation alone does not provide adequate protection against the effects of solid-fuel stoves. Thus, the ideal solution would be to replace the solid-fuel stoves with stoves that use liquid fuel or gas. Since resources are limited in developing countries, vented solid-fuel stoves may be the more economically feasible solution.
In general, environmental determinants of health are heavily influenced by public and private decisions regarding education, economic development, employment, housing and more. In other words, every policy decision on housing, education and employment is a health policy decision as well. The Millennium Development Goals provide “a broad international policy and development framework that addresses the threats to health from environmental conditions.”(10) This framework is based on the understanding that the health of the environment is inextricably linked to human health, and that solutions must seek to reduce environmental hazards while simultaneously changing human behavior.
(1) Jacoby M, Gorenflo D, Black E, Wunderlich C, Eyler AE. Rapid repeat pregnancy and experiences of interpersonal violence among low-income adolescents. Am J Prev Med. 1999;16:318-321.
(2) Dubos R, Savage D, Schaedler R (1966) Biological Freudianism, lasting effects of early environmental influences. Pediatrics, 38:789–800.
(3) Ehiri, J. Maternal and Child Health: Global Challenges, Programs, and Policies. Springer. New York: New York, 2009.
(5) Ehiri, J. Maternal and Child Health: Global Challenges, Programs, and Policies. Springer. New York: New York, 2009.
(6) Bruce N, Perez-Padilla R, Albalak R. Indoor air pollution in developing countries: a major environmental and public health challenge. Bulletin of theWorld Health Organization 2000; 78:1078–1092.
(7) Fitzpatrick, Tony. "Cooking Smoke Serious Global Health Risk." Albion Monitor. 7 Jan. 1997. Web. 28 Apr. 2010.
(9) Pokhrel AK, Smith KR, Khalakdina A, Deuja A, Bates MN. Case-control study of indoor cooking smoke exposure and cataract in Nepal and India. Int J Epidemiol. 2005;34:702–708.
(10) Ehiri, J. Maternal and Child Health: Global Challenges, Programs, and Policies. Springer. New York: New York, 2009.