Ghanaians working in Agbogbloshie, a suburb of Accra, Ghana.Marlenenapoli, Wikimedia Commons

For the first time since 2007, the Blacksmith Institute based in New York and Green Cross Switzerland are pointing fingers on not just what, but where in the world the toxic threats are the worst.

In previous years, the two institutes have identified the top toxic threats and clean-up successes as seen on a global scale. Last year's number one threat for example was lead exposure from lead-acid rechargeable car battery recycling sites.

"In this year's report, we cite some of the most polluted places we've encountered. But it is important to point out that the problem is really much larger than these ten sites," says Richard Fuller, president of Blacksmith Institute in a press release. "We estimate that the health of more than 200 million people is at risk from pollution in the developing world."

Some of the sites listed in the 2007 report are still so devastating to human health as to be included again in 2013, those sites are marked here with an * at the top of this list. Others, such as two sites in China, have made enough improvements to be removed from this list and replaced with other areas such as Agbobloshie, an e-waste processing site in Accra, Ghana, and Kalimantan, Indonesia, which has become contaminated with mercury resulting from small-scale gold mining. The list, presented here is not ranked.

Agbobloshie, Ghana

What's needed to help recycle 215,000 tons of secondhand consumer electronics in Ghana? Something better than hand wire-stripping tools, which were introduced in 2010 as an attempt reduce the still prevalent practice of burning sheathed cables to recover the interior copper.

"Styrofoam packaging is utilized as a fuel to burn the material in open areas. Cables can contain a range of heavy metals, including lead. To some extent, these metals can migrate through particulate in the smoke, while significant amounts are also left behind on area soils," reported the institutes. They site lead levels as high as 18,125 ppm found in the soil around Agbogbloshie near food markets and homes. In the United States, the Environmental Protection Agency standard for lead in soil is 400 ppm.

Currently, the Blacksmith Institute and partners are working to mechanize the wire-stripping process. Their plan is to introduce work stations equipped with machines that would wire-strip the cables, centralizing the recycling process and reducing wide-spread communal exposures to air pollution.

A view of a radioactive sign near a shelter and containment area built over the destroyed 4th block of Chernobyl's old nuclear power plant on August 2qqaz25, 2013.GENYA SAVILOV/AFP/Getty Images

Not surprising that Chernobyl hasn't made if off the World's Most Polluted Sites list. The concrete casing that was placed over the reactor soon after the meltdown of its core on April 26, 1986, was only meant to contain the remaining fuel and absorb radiation for at most 30 years. The current replacement structure for this "sarcophagus" has encountered several delays and is not expected to see completion until 2016.

NEWS: Roof Collapses at Chernobyl Nuclear Plant

Radioactive dust including uranium, plutonium, cesium-137, strontium-90, and other metals continue to plague the 19-mile exclusion zone around the nuclear plant. Should the current casing fail before the new containment is in place, the number of people at risk in Ukraine, Russia, Moldova and Belarus is estimated between 5 and 10 million. Today, prolonged low-dose exposure in neighboring areas has contributed to a significant increase in the risk of leukemia, according to studies sited by Blacksmith Institute and Green Cross.

The institutes noted that Fukushima, Japan, while not listed in the top 10, deserved special recognition. A World Health Organization report in 2013 predicted that "for populations living around the Fukushima nuclear power plant there is a 70 percent higher risk of developing thyroid cancer for girls exposed as infants, a 7 percent higher risk of leukemia in males exposed as infants, a 6 percent higher risk of breast cancer in females exposed as infants and a 4 percent higher risk, overall, of developing solid cancers for females."

Environmental activists take part in a protest against the pollution of the Citarum river in Bandung on September 28, 2012. TIMUR MATAHARI/AFP/GettyImages

Labelled "the most-polluted river in the world" by a local commission of government agencies and NGOs charged with its clean-up, Citarum river provides 80 percent of the surface water to Jakarta’s water supply authority, irrigates farms that supply 5 percent of Indonesia’s rice, and is a source of water for upwards of 2,000 factories.

The pollution of numerous chemicals including lead, cadmium, chromium, and pesticides affects about 500,000 people directly, and as many 5 million people indirectly.

In 2008, the Indonesian Government received a 500 million dollar loan from the Asian Development Bank as part of a 3.5 billion-dollar plan to rehabilitate the Citarum over 15 years. Environmental activists however find the clean-up progress slow.

A 2013 APN Science bulletin found that aluminum was at 97 ppb (the world average is 32 ppb); manganese in the river was at 195 ppb (world average: 34 ppb); and iron concentrations in the Citarum were 194 ppb (world average: 66 ppb), reported Blacksmith Institute and Green Cross.

PHOTOS: Going Blue: Ocean Landscapes Need Protection

View of the city of Dzerzhinsk from an airplane.Cyrios, Wikimedia Commons

The Guinness Book of World Records named Dzershinsk the most polluted city in the world in 2007 following tests of the water supply. About 300,000 tons of chemical wastes were improperly stored in landfills between 1930 and 1998 during the height of Russia's chemical weapons manufacturing. An identified 190 different chemicals have since leached into the groundwater, including thousands of times higher than recommended levels of dioxins and phenol.

The average life expectancy for the city of 245,000 is only 47 for women and 42 for men.

7 Most Disgusting Wonders of the World

A worker uses boots to avoid dirty water and harmful chemicals while treating leather skins.Raa Jonathan/Getty Images

Imagine some 250 processing plants shoved all at one end of Central Park where about 10,000 people work wearing only rubber boots for protection to treat the hides of animal skins sold later as fine leather goods around the world. Then imagine dumping 22,000 cubic liters of the toxic waste produced from the tannery process into the East River and use that as the main water supply for the surrounding city of 185,000 people and you'll start to have an idea about the problems facing Hazaribagh.

9 Popular Cities Losing War with Rising Seas

Besides the risk of exposure to the cancer-causing hexavalent chromium, "acid burns, rashes, aches, dizziness, and nausea are also common health problems faced by local residents," reported Blacksmith Institute and Green Cross.

ANALYSIS: Papyrus To Purify River of Blood

A boy digs for lead in Kabwe, Zambia.Blacksmith Institute

The Zambian government relied on a World Bank and Nordic Development Fund of $26 million between 2003 to 2011 to reduce childhood exposure to lead in its second largest city. But children in Kabwe are growing up with an average of 50 and 100 ug/dL of lead in their bloodstream. The Centers for Disease Control recommended exposure level is 5 ug/dL.

The problem is children and teens are playing and working in leftover tailing piles of the now closed lead mine.

White Water Rafting: 5 Amazing Locations around the Globe

Workers are seen in a nest of illegal gold mining rigs at Lake Serantangan in Singkawang off the Indonesia's West Kalimantan province December 7, 2012.YUSUF AHMAD/Reuters/Corbis

Artisanal, small-scale gold mining is prevalent around the world, but too often it is also done with mercury -- which binds to the gold, allowing for a rudimentary collection process, and can then be burned off with simple smelting. The result is gold rush of toxic waste.

"The United Nations Industrial Development Organization (UNIDO) estimates that more than 1,000 tons of mercury are released into the environment each year through this process, which constitutes about 30 percent of the anthropogenic mercury emissions," reported Blacksmith Institute and Green Cross.

PHOTOS: Journey to the South Pacific

The mercury enters the ecosystem both during the collection phase, when it leaks into the waterways, and during the smelting process, when it is released into the atmosphere. Additionally, many miners smelt within their own homes.

Some 43,000 people make a living as illegal, small-scale gold miners in Central and South Kalimantan, the Indonesian portion of the island of Borneo. "One miner said his earnings reached $350 a month, exceeding more than three time the regional minimum wage," reported Reuters.

The concentration of mercury in the Kahayan River of Central Kalimantan was 2,260 ng/L in 2008, more than twice Indonesia’s standard for total mercury in drinking water (1,000 ng/L).

NEWS: 'Toxic bomb' Ticks on Maldives Trash Island

Fausto -- who works in the local aggregate industry, unloading sand and gravel from rafts -- sips mate as he looks from the Isla Maciel neighborhood to the Matanza-Riachuelo river on February 3, 2010 in Buenos Aires, Argentina. Sub.Coop/LatinContent/Getty Images

An estimated 15,000 industries are actively releasing effluent into the Matanza-Riachuelo River, considered the most important waterway in Buenos Aires and crosses 14 municipalities.

About 60 percent of the approximately 20,000 people who reside along the banks of the river live in territory deemed unsuitable for human habitation, with 6 percent living in the water basin’s most unsuitable conditions, namely slums and villas with no sewage system or access to potable water.

A study this year found that 80 percent of the wells near the river basin were not safe for drinking due to contamination levels of zinc, lead, copper, nickel, and chromium. Gastrointestinal diseases, respiratory diseases, and cancer are significant public health problems for the region.

PHOTOS: Argentina's Bergoglio Becomes Pope Francis

A boat guide drives a speed boat as oil slick splashes on the water through the Bodo creek in Ogoniland near Nigeria's oil hub city of Port Harcourt Dec. 4, 2012.AKINTUNDE AKINLEYE/Reuters/Corbis

"An average of 240,000 barrels of crude oil are spilled in the Niger delta every year," reports Blacksmith Institute and Green Cross.

"The spills have not only contaminated the surface and ground water of the delta but also the ambient air and locally grown crops with hydrocarbons, including known carcinogens like polycyclic aromatic hydrocarbons (PAHs)."

Despite billions of dollars worth of oil flowing out of Nigeria South East, life for the majority of Niger Delta's inhabitants remains unchanged. Most people live in modest iron-roofed shacks, and rely on farming or fishing -- their only interaction with the oil industry being when they step over pipelines in the swamps, or when a spill blights their landscape.

These spills affect the environment and in turn the health of the population. "One article published in the Nigerian Medical Journal in 2013 estimated that the widespread pollution could lead to a 60 percent reduction in household food security and a 24 percent increase in the prevalence of childhood malnutrition," reported the institutes.

Best and Worst Places to Grow Old

A band of domra players from Norilsk Arts College, perform in safety helmets at Oktyabrsky Mine. Kozhevnikov Denis/Corbis

From 1935 until the turn of the 21st century, the city of Norilsk contained the world’s largest heavy metals smelting complex. As a result, the estimated population of over 130,000 people are still exposed to air contaminated with nearly 500 tons each of copper and nickel oxides and 2 million tons of sulfur dioxide released annually.

Though this image shows Norilsk residents keep their spirits up with music, life expectancy for factory workers is 10 years below the Russian average.