Each continent has its own ecological bane that always gets on the list of the worst polluted places on our globe. Be it dirty air of North America's cities or extremely contaminated soils found in the smelting hubs of Africa or South America, these places beg for mercy and some substantial clean-up programs. You will not include these locations in your next itinerary, unless you need a warning and reminder of how people should not treat the Earth.

North America.

The three most polluted cities on the North American continent are Pittsburgh in the USA, Windsor in Canada and Mexico City in Mexico.

Pittsburgh. The U.S.A.

Polluted air is a serious threat to 189 million United States' residents and six in ten Americans live in cities where the level of ozone or particle pollution is so high that it can lead to asthma, bronchitis, heart attack and even death. Pittsburgh, the second largest city in the state of Pennsylvania, is an example of one of the most polluted cities in the country.

It comes as a big surprise that over recent years Pittsburgh has many times been named "the most livable city in the USA". Still, according to the American Lung Association's annual report, the city has reported the highest short-term particle pollution (amount of tiny solid and liquid particles in the air such as soot or exhaust) and the second highest year-round levels. Main sources of such pollution are cars, coal-fired power plants and steel industry. Some researches claim, however, that the city's air pollution comes from the factories in Ohio.

Windsor. Canada.

Windsor, the major city of Southwestern Ontario, Canada, is the country's hub of the automobile industry. However, its main source of air pollution is the industry located in the U.S. The city is situated at the Canada-U.S. border, and therefore, around 90% of smog comes from the American side. By the way of example, there are four coal-fired power plants in Ontario, while U.S. Midwest is home to around 250 such plants.

In 2008 Robert F. Kennedy Jr., an environmental activist, claimed that American companies made Windsor "the most polluted city in North America." According to Kennedy, the city reports some of the highest cancer rates and respiratory illnesses rates in Canada. In turn, the Weather Network has named Windsor "the smog capital of Canada", the channel underlines, however, that one of the main sources of poor air quality are vehicle emissions.

Mexico City. Mexico.

The capital of Mexico and one of the world's most populated cities is an ecological trap due to its geographical location. The city is situated in a valley, around 7,300 feet (2,240 meters) above sea level, so the air is really thin and the exhausts get trapped. Moreover, the winds in circulation are too weak to diffuse the contaminated air outside the metropolis.

The recent research reveals that the smog hanging over the city is a serious threat to its residents, especially children. Apparently, Mexico's polluted air prevents lungs from growing and working properly. According to National Public Health Institute, the effect of exposure to contaminated air in Mexico City is bigger than the effect of exposure to maternal smoking among children in the U.S.

To alleviate the problem of air pollution local and federal authorities have been implementing various plans, which include closing factories, " A day without a car" programs , modernizing old buses and promoting the use of bikes.

South America

La Oroya. Peru.

The town of about 33,000 residents, situated in the central part of Peru, is home to enormous smelting industry. The first copper smelter emerged in La Oroya in 1922 and since then many other plants and refineries followed. The town's heavy industry has transformed this little mountain village into one of the most polluted places on the globe. Among most serious pollutants found in La Oroya is lead, which is especially devastating to children's health. 99% of children living in the town have high degree of lead in their blood, which is especially harmful to kids' mental development.

The Missouri-based Doe Run, which owns the smelting business in La Oroya, has been obliged to implement an environmental management plan that will reduce the emissions. In some areas the progress has been made as the company has managed to lower some emissions and has invested (jointly with the Peruvian Ministry of Health) $1 million yearly in the program designed to reduce blood lead levels in the area. The ecologists underline, however, that the sulfur dioxide emissions have remained very high in the town and lead will stay in the area's soil for centuries.

Europe

Pernik. Bulgaria.

Pernik, a town of about 90,000 inhabitants situated near Sofia, is considered to be the worst polluted place in the country and the entire European Union. In the mid-20th century the development of coal industry commenced in the region, transforming Pernik into the energy center of Bulgaria. Today the town is home to a large number of metallurgy plants that cause extreme pollution in the region. According to the recent report revealed by the EU, the average dust concentration in Pernik totals 92 microgrammes per cubic meter, which is the highest level among the EU member states, which report 30 mg of dust level on average.

Apparently, Bulgaria itself is the most contaminated country among European Union states. It is filled with old cars with no catalytic converters and there are plenty second-hand vehicles from western European countries. Moreover, most of the country's small towns use coal-fired heating during winter, which is a great contributor to unhealthy emissions.

Chernobyl. Ukraine.

Chernobyl, a small town in northern Ukraine, near the border with Belarus, is associated with the Chernobyl accident - the worst nuclear power plant disaster in history. The accident occurred in April 1986 causing many deaths mainly due to the radiation poisoning. About 336,000 people living in some areas of Ukraine, Belarus and Russia had to be evacuated because of extreme contamination, and nuclear rain was observed in Central, Western, and as fas as Northern Europe.

Today Chernobyl remains one of the most polluted places on Earth. There is a 19-mile (30 km) exclusion zone around the town where people are not allowed to live. Still, between 1992 and 2002 around 4,000 of thyroid cancer cases were found among children living near the zone.
According to various estimates between 60 and 200 years is needed before the land could be used for some industrial purposes, and farming would be very dangerous for at least 200 years. The place where Reactor #4 exploded is estimated to be fully safe in 20,000 years.

Asia

Norilsk. Russia.

Norilsk, the second largest city above the Arctic Circle, inhabited by about 130,000 people, is the mining and smelting industry hub of Russia. The first plants appeared in the town in the 1930s and today Norilsk is home to the world's largest smelting complex. The town of acid rain and smog is the country's greatest polluter - it releases 500 tones of each copper and nickel oxides and 2 million tons of sulfur dioxide annually.
The main culprit for this situation is Norilsk Nickel, a huge firm that controls one-third of the world's nickel deposits and is Russia's main producer of nickel, cobalt, platinum and palladium.

Such heavily contaminated air causes serious health problems such as respiratory diseases, higher mortality, pregnancy complications and lung cancer. According to the Blacksmith Institute, an organization supporting pollution-related environmental projects, "children living near the nickel plant were shown to become ill at a rate 1.5 times higher than children from further districts."

Linfen. China.

Smog covers the city of Linfen that sits along the banks of the Fen River in China. In 2007 the city, home to around 4 million people, was considered by the Blacksmith Institute the world's most polluted town. Linfen is home to an enormous coal industry, filled with hundreds of legal and illegal mines, steel plants and refineries, providing almost two thirds of China's energy. The air is dark in the town and its inhabitants literally choke on coal dust. The level of sulfur dioxide and other particulates exceeds any acceptable limits and there is a shortage of water due to contamination of drinking water sources by arsenic.

The Linfen's residents suffer from various diseases such as lung cancer, bronchitis, pneumonia, and the children's blood lead level is many times higher than any acceptable norms.

According to the World Bank, 16 out of 20 of the world's most polluted cities in terms of air quality are in China.

Africa

Kabwe. Zambia

Kabwe, home to 210,000 residents, is the capital of Zambian Central Province, Zambia. In 1902 lead and zinc deposits were found in the town and soon after the smelting and mining industry were set up and operated until 1994. The plants were closed down but they left the city's soil and water polluted by lead and metals. Children's blood lead levels are up to 10 times higher than the acceptable limits set by the U.S. Environmental Protection Agency.

Since 2007 some serious actions have been undertaken to clean up the most contaminated areas of Kabwe. By the way of example, the World Bank allocated $40m for a clean-up program and the Nordic Development Fund granted $10m to the region. In fact, many areas of the town still need to be relocated.