Michael McCally

Health risks posed by use of Di-2-ethylhexyl phthalate (DEHP) in PVC medical devices: a critical review.

BACKGROUND Polyvinyl chloride plastics (PVC), made flexible through the addition of di-2-ethylhexyl phthalate (DEHP), are used in the production of a wide array of medical devices. From the late 1960s, leaching of DEHP from PVC medical devices and ultimate tissue deposition have been documented. METHODS A critical review of DEHP exposure, metabolism, and toxicity data from human and animals studies was undertaken. A brief analysis of alternatives to DEHP-plasticized PVC for use in medical device manufacture was completed. RESULTS DEHP leaches in varying concentrations into solutions stored in PVC medical devices. Certain populations, including dialysis patients and hemophiliacs may have long-term exposures to clinically important doses of DEHP, while others, such as neonates and the developing fetus, may have exposures at critical points in development. In vivo and in vitro research links DEHP or its metabolites to a range of adverse effects in the liver, reproductive tract, kidneys, lungs, and heart. Developing animals are particularly susceptible to effects on the reproductive system. Some adverse effects in animal studies occur at levels of exposure experienced by patients in certain clinical settings. DEHP appears to pose a relatively low risk of hepatic cancer in humans. However, given lingering uncertainties about the relevance of the mechanism of action of carcinogenic effects in rodents for humans and interindividual variability, the possibility of DEHP-related carcinogenic responses in humans cannot be ruled out. CONCLUSIONS The observed toxicity of DEHP and availability of alternatives to many DEHP-containing PVC medical devices presents a compelling argument for moving assertively, but carefully, to the substitution of other materials for PVC in medical devices. The substitution of other materials for PVC would have an added worker and community health benefit of reducing population exposures to DEHP, reducing the creation of dioxin from PVC production and disposal, and reducing risks from vinyl chloride monomer exposure.

Poverty and Ill Health: Physicians Can, and Should, Make a Difference

Poverty and social inequalities may be the most important determinants of poor health world-wide. Socioeconomic differences in health status exist even in industrialized countries where access to modern health care is widespread [1]. In this paper, we make a formal argument for physician concern and action about poverty based on the following assertions. Physicians have a professional and a moral responsibility to care for the sick and to prevent suffering. Poverty is a significant threat to the health of both individual persons and populations; thus, physicians have a social responsibility to take action against poverty and its consequences for health. Physicians can help improve population health by addressing poverty in their roles as clinicians, educators, research scientists, and participants in policymaking. Concepts of Poverty and Health Poverty is a multidimensional phenomenon that can be defined in both economic and social terms. An economic measure of poverty identifies an income sufficient to provide a minimum level of consumption of goods and services. A sociologic measure of poverty is concerned not with consumption but with social participation [2]. Poverty leads to a persons exclusion from the mainstream way of life and activities in a society [3]. There is a difference between absolute poverty, which implies a lack of resources deemed necessary for survival in a given society, and relative poverty, which is defined in relation to the average resources available in a society. Economic measures are easy to obtain, but social measures may provide a better understanding of the causes and consequences of poverty. Steps have been taken toward the development of indices of deprivation, which have promising uses in health services and public health research [4]. In 1978, the World Health Organization (WHO), in the Alma-Ata Declaration, spelled out the dependence of human health (defined broadly) on social and economic development and noted that adequate living conditions are necessary for health [5]. Despite their knowledge of this, governments and major development organizations have largely continued to view health narrowly as a responsibility of the medical sector, outside the scope of economic development efforts. Consequently, governments have encouraged many large-scale but narrowly focused economic development efforts, ignoring the connection between poverty and health [6]. In developed countries, governments promote various practices, such as heavy pesticide applications, that are designed to increase economic development and competitiveness but that are environmentally unsound and personally unhealthy. Poverty Causes Death and Illness on a Massive Scale During the second half of the 1980s, the number of persons in the world who were living in extreme poverty increased. Currently, extreme poverty afflicts more than 20% of the worlds population. A recent report from WHO points out that up to 43% of children in the developing world-230 million children-have low height for their age and that about 50 million children have low weight for their height [7]. Micronutrient malnutrition (deficiencies of vitamin A, iodine, and iron) affects about 2 billion persons worldwide. It has been estimated that if developing countries enjoyed the same health and social conditions as the most developed nations, the current annual toll of more than 12 million deaths in children younger than 5 years of age could be reduced to less than 400 000. An average person in one of the least developed countries has a life expectancy of 43 years; the life expectancy of an average person in one of the most developed countries is 78 years [7]. This is not to deny that real gains in health have occurred in recent decades. For example, since 1950, life expectancy at birth in several developing countries has increased from 40 to more than 60 years. Similarly, worldwide, mortality rates for children younger than 5 years of age decreased from 280 to 106 per 1000, on average. Some countries show much sharper declines [7], but indices of health in these countries still fall far short of those in wealthier nations. Poverty and Sustainable Development The relation between poverty and health is complex, and we believe that it is best understood in the framework of a new notion of ecosystem health, which places poverty and health in the nexus of environment, development, and population growth [8]. Ecosystems provide the fundamental underpinning for public health in both developed and less developed countries, not only through food production, for example, but also through their roles in economic development. For instance, they supply forest resources and biomass fuels and serve as habitats for the vectors of disease [9]. Sustainability is produced by using resources in ways that meet the needs of current populations without compromising the ability of future generations to meet their own needs [10] and is predicated on the need to ensure a more equitable sharing of todays resources. Meeting the needs of the worlds poor implies limitation of the current use of resources by industrialized nations. Barriers to the benefits of development include rapid population growth, environmental degradation, and the unequal distribution of resources. At one extreme, traditional, preindustrial societies are characterized by relatively high birth rates coupled with high death rates attributable to acute infectious diseases and the hazards of childbearing; this leads to slow population growth. At the other extreme, in the most developed countries, population stability has occurred. In the intermediate situation, in less developed countries, population stability has not been reached, and the global population thus continues to increase. In some less developed countries, a demographic trap exists in which the development of resources cannot keep pace with the requirements of the growing population and poverty is worsened [11]. The most developed countries escape the trap by buying additional essential resources in the global marketplace to make up the difference. Environmental degradation exaggerates the imbalance between population and resources, increases the costs of development, and increases the extent and severity of poverty. For example, the need for fuel wood, timber for export, and farmland results in deforestation, which increases soil erosion, flooding, and mud slides and reduces agricultural productivity. As a result, biological diversity is lost, production becomes increasingly reliant on pesticides and fertilizers, and use of expensive fossil fuels increases. Water is a critical resource. In Punjab, the breadbasket of India, the major aquifer is decreasing at a rate of 20 cm per year, threatening health by reducing agricultural productivity and the supply of clean water [12]. Economic development without regard to long-term environmental and social consequences also threatens sustainability by damaging the systems that sustain healthy communities. Inequalities in Health Are Socially Determined The strong and pervasive relation between an individual persons place in the structure of a society and his or her health status has been clearly shown in research conducted over the past 30 years [13-16]. In 1973, Kitagawa and Hauser [17] published convincing evidence of an increase in the differential mortality rates according to socioeconomic level in the United States between 1930 and 1960. They found that rates of death from most major causes was higher for persons in lower social classes. In Britain, research into health inequalities was summarized in 1980 in The Black Report [18], which was updated in 1992 [19] and is currently under review by an official working group. The report was prepared by a labor government-appointed research working group chaired by Sir Douglas Black, formerly Chief Scientist at the Department of Health and, at the time, President of the Royal College of Physicians. The Black Report concluded that there are marked inequalities in health between the social classes in Britain (Figure 1). Marmot and colleagues, in the well-known Whitehall studies of British civil servants begun in 1967, showed that mortality rates are three times greater for the lowest employment grades (porters) than for the highest grades (administrators) and that no improvement occurred between 1968 and 1988 [20-22]. Figure 1. Comparison of standardized mortality ratios for men 15 to 64 years of age by social class over five decades in England and Wales. Such findings could, in theory, be due to differences in age, smoking, nutrition, types of employment, accident rates, or living conditions, but the Whitehall study participants were from a relatively homogeneous population of office-based civil servants in London. They had largely stable, sedentary jobs and access to comprehensive health care. A second observation of the Whitehall investigations, confirmed by the Multiple Risk Factor Intervention Trial (MRFIT) studies in the United States, is that conventional risk factors (smoking, obesity, low levels of physical activity, high blood pressure, and high plasma cholesterol levels) explain only about 25% to 35% of the differences in mortality rates among persons of different incomes (Figure 2) [23, 24]. Figure 2. Income and age-adjusted mortality rates among 300 000 white men in the United States. An equally striking finding is Wilkinsons observations of the relation between income distribution and mortality [25, 26]. Wilkinson assembled two sets of observations. First, he found no clear relation between income or wealth and health when comparisons were drawn between countries (for example, there is no relation between per capita gross domestic product and life expectancy at birth in comparisons between developed countries at similar levels of industrialization). But Wilkinson also showed a strong relation between income inequality and mortality within

Climate change, water resources and child health

Climate change is occurring and has tremendous consequences for childrens health worldwide. This article describes how the rise in temperature, precipitation, droughts, floods, glacier melt and sea levels resulting from human-induced climate change is affecting the quantity, quality and flow of water resources worldwide and impacting child health through dangerous effects on water supply and sanitation, food production and human migration. It argues that paediatricians and healthcare professionals have a critical leadership role to play in motivating and sustaining efforts for policy change and programme implementation at the local, national and international level.

Health and safety risks of carbon capture and storage.

CARBON CAPTURE AND STORAGE (CCS) IS A TECHnology being developed in an attempt to slow global warming. In theory, CCS would prevent carbon dioxide produced from coal-fired power plants from reaching the atmosphere by capturing and storing it permanently underground. The scale of this proposal is remarkable, requiring the capture of tens of billions of tons of carbon dioxide from thousands of coal and gas power plants throughout the world. Although carbon dioxide has been injected underground to enhance oil recovery from old wells, the use of the technology to permanently store carbon dioxide is still in a demonstration phase. Carbon capture and storage may receive billions of dollars of taxpayer support in pending energy legislation, the American Clean Energy and Security Act passed by the US House of Representatives in June 2009. Despite widespread political support for the technology, important and unanswered questions remain regarding CCS development. What risks to human health and safety are involved? How will CCS projects affect water quality in aquifers? Can CCS at scale really work and can carbon dioxide storage be made permanent? The risks are substantial and to our knowledge have not been considered in the promotion of CCS technology.

The challenges of emerging illness in urban environments: An overview

The New York City West Nile outbreak is an important case study for examining several medical and public health issues raised by the specter of emerging illnesses in urban areas. Five specific issues are addressed in this issue of theJournal of Urban Health: ecosystem health, vector (e.g., mosquito) control, risk communication, public health infrastructure, and parallels between this outbreak and bioterrorism.

Five years down the road from Rio.

Five years ago in Rio de Janeiro the earth summit agreed on Agenda 21, a 40 chapter plan of action for achieving sustainable development. Progress has been poor, heads of state and environmental ministers heard at a special session of the general assembly of the United Nations last week,1 but it was not all bad news. Some promising developments have occurred in international policies and agreements. And we now know more about those aspects of global change with important implications for human health: global warming, the loss of biodiversity, and persistent organic pollutants.2 3 4 5 Global warming will probably bring extremes of weather, new infectious illnesses, threats to food production, flooding, forced migration, and a rise in sea level. Destruction of habitats and extinction of species result in the loss of materials for medical research and ecological services (such as water cleansing, pollination, and soil production) necessary for good health. Organic pollutants, particularly chlorinated hydrocarbons, may contribute to the rising incidence of reproductive disorders. Since 1992, limited progress has been …