About the List
Problems Are More Than Just A Few Sites
This year’s report sets out a range of pollution problems and for each gives a brief summary of the problem’s source and scope. The list of problems is drawn primarily from the Blacksmith Institute database of polluted places, as well as from suggestions by relevant experts.
Blacksmith Institute’s database contains about 600 sites nominated by individuals or groups, or identified by Blacksmith and other organizations in the field. These range from whole cities that are choking on air pollution, to complete rivers that are black and stinking, to small facilities that pose a toxic threat to a neighborhood, to villages whose water supply has turned orange and noxious. The emphasis in the database, being in line with Blacksmith Institute’s mission, is on legacy sites or clusters of polluters where there is no clear responsible party.
This year’s report provides five lists drawn from a larger “Toxic Twenty” set of pollution challenges; problems that are repeatedly found both in health and pollution literature, and in Blacksmith Institute and Green Cross project work.
Top Ten World's Worst Pollution Problems
The “Top Ten World’s Worst Pollution Problems” is a non-ranked set of global issues, which – in the overall judgment of a panel of expert advisors – represent ongoing activities and conditions that pose the greatest threat to human health. This judgment requires a balance between problems with widespread but moderate contamination levels, and problems that are smaller but much more toxic. There can always be debate about such judgments, but there is no denying that each of the Top Ten Worst Pollution Problems represents a worldwide threat to human health and development.
Each Pollution Problem has its own particular characteristics that separate it in some way from the others. Some of the problems, like heavy metals and persistent organic pollutants (POPs), remain for generations and continue to have a residual impact long after use. Others, like contaminated surface water, have a particularly damaging impact on the health of children. For this reason we have also created these subsidiary lists.
- The Top Four Least Addressed Pollution Problems
- The Top Eight Pollution Problems Affecting Children
- The Top Seven Pollution Problems in Africa
- The Top Four Pollution Problems Affecting Future Generations.
Ranking
This year’s ranking criteria is based on the system used in previous years to determine the World's Worst Polluted Places. It has been adjusted appropriately to account for the new direction of the report.
There are three primary factors taken into consideration when ranking the Top Ten and Toxic Twenty: Pollutant, Pathway and Population.
We first determine the severity or toxicity of the Pollutant. More innocuous contaminants receive a lower ranking, while more dangerous substances, say mercury or lead, garner a higher ranking.
Secondly, we evaluate the Pathway, or how the pollutant is transferred to the population. People absorb contaminants through direct inhalation, by drinking contaminated water, by inhaling airborne dust, by bathing in contaminated water, by eating contaminated foodstuffs, or through direct skin contact. The more direct, the more concentrated and therefore more dangerous the pathway, the higher the ranking the problem receives.
Finally, we evaluate the Population. Here, population refers to the overall number affected by the pollutant globally. Those problems affecting the most people are ranked highest in this category.
Given the uncertainties in such assessments, the problems within the Top Ten list are NOT RANKED against each other and therefore are presented in alphabetical order.
Pollution is a Major Factor in Disease
Industrial wastes, air emissions, and legacy pollution affect over a billion people around the world, with millions poisoned and killed each year. People affected by pollution problems are much more likely to get sick from other diseases. Other people have reduced neurological development, damaged immune systems, and long-term health problems. Women and children are especially at risk. The World Heath Organization estimates that 25 percent of all deaths in the developing world are directly attributable to environmental factors.
A study, published in 2007 by a Cornell research group found even more alarming results. The team surveyed 120 relevant articles, covering population growth, pollution and disease and found that an astonishing 40 percent of deaths worldwide were caused by water, air and soil pollution.
Children are Especially Affected
More than other leading causes of death, those tied to environmental factors have a disproportionate effect on children. Of the 2.2 million people killed by diarrhea in 1998, most were less than five years of age, and nearly two million were under 192. Up to 90% of diarrheal infections are caused by environmental factors like contaminated water and inadequate sanitation. Similarly, acute respiratory infections, 60% of which can be linked to environmental factors, kill an estimated two million children under five every year.
Children are more susceptible to environmental risks than adults. Children are not just “small adults,” but rather are physiologically different and more vulnerable. By way of illustration, while children only make up 10% of the world’s population, over 40% of the global burden of disease falls on them. Indeed, more than three million children under age five die annually from environmental factors.
The Death Toll is not the Only Impact of Pollution
Annually millions of lives are made markedly more difficult through constant illness, neurological impairment and lost life years. By way of example, the presence of lead in children lowers I.Q. by an estimated 4-7 points for each increase of 10 μg/ dL. While the acuteness of the pollution varies from site to site, our database identifies populations around the globe with blood lead levels ranging from 50 -100 μg/dL, up to 10 times recommended levels.
Despite this pollution pandemic, shockingly little is being done in response. With regard to international assistance and public health, large amounts of resources have been leveraged to combat some of the worst killers like HIV/AIDS, Malaria and TB. While much attention has been paid to these diseases, the relationship between human health and pollution seems to have been largely ignored. Indeed only a fraction of international aid is allocated to remediation of critical sites, despite the significant threat posed by pollution, and the proven efficacy of interventions. In other words, there is a great deal more to be done.
Combating the health threat posed by pollution can be done affordably and effectively. In 2007, Blacksmith Institute used a standard methodology to compare some of its projects with other public health interventions. Among other findings, Blacksmith determined that some of its projects cost between $1 - $50 per year of life gained. This compared favorably to the $35 to $200 per year of life gained for World Bank estimates on interventions related to water supply, improved cooking stoves and malaria controls.
To be clear, the Pollution Problems presented in this report are some of the biggest killers in the world – and many can be stopped effectively and affordably.
Impacts of the Top Ten
Some of pollution problems, although ubiquitous, are less acute than others. An estimated 80% of the world’s households cook with unprocessed biomass fuels on rudimentary stoves in poorly ventilated kitchens. Indoor air pollution particularly affects women and children, resulting in, among other effects, increased incidence of acute respiratory illness.
Others, while still widespread, affect fewer people with more severity. Acute lead poisoning resulting from informal car battery recycling can kill very quickly at certain levels. More commonly, lead has debilitating effects on neurological development, resulting in lives made that much harder in some of the poorest countries in world.
Hence, in this year’s report, Urban Air Pollution ranks alongside Used Lead Acid Battery Recycling and Artisanal Gold Mining. Readers are likely aware of the health threat posed by air pollution in some of the world’s major cities, like Beijing or Mexico City. Those same readers, however, may not even be aware of Artisanal Gold Mining, let alone its pollution component. This only underscores the importance of ranking these problems in this way.
There are an estimated 10-15 million Artisanal Miners worldwide who mine for gold. These miners use mercury to form an amalgam with the gold contained in mined soil. That amalgam is later burned; evaporating the mercury while leaving behind gold. The evaporated mercury is extremely toxic if inhaled and then quickly condenses and finds its way into local water supplies, where it is either ingested directly by humans, or bio-accumulates in fish, which in turn are eaten by humans. An estimated one third of global mercury emissions come from these activities, yet the problem is largely unknown. This underscores the importance of this report; that global killers are often silently taking lives around the world. The goal of this report is to illuminate these preventable deaths for the international community.
