Wikipedia
Cubatão is a city in the state of São Paulo, Brazil, 12 kilometers away from Santos seaport, the largest in Latin America. It is part of the Metropolitan Region of Baixada Santista. The population is 127,006 (2015 est.) in an area of 142.88 km². It hosts industries, refining oil, steel mills and fertilizers.
In the early 1980s, Cubatão was one of the most polluted cities in the world, nicknamed "Valley of Death", due to births of brainless children and respiratory, hepatic and blood illnesses. High air pollution was killing forest over hills around the city. It's a rich town with a poor population. It was ranked the top ten dirtiest cities in the world by Popular Science.
On February 25, 1984 an oil spill set the shantytown Vila Socó on fire, killing 93 people according to official figures, though the actual death toll may be more than 200. The contamination of workers with persistent organic pollutants put Rhodia into Greenpeace's top 10 world's worst corporate crimes ever in its report to Rio Summit in 1992.
Strong efforts were made to diminish pollution in the city, costing $1.2 billion so far. Although things have improved a lot, it is impossible to completely clean the soil and groundwater and while many large industries continue to work in such a small area, there will always be some pollution.