European companies are accused of taking advantage of weak fuel standards in African countries to export highly-polluted fuel to West Africa, a new report says. The report, from the Swiss watchdog group of Public Eye, said major European oil companies and commodity traders take crude oil from African countries, blend it with highly-polluted additives, and then sell it back to them. “Many West African countries that export high grade crude oil to Europe receive toxic low quality fuel in return,” it wrote.

Toxic products that the companies add to make the so-called “African Quality” fuels are far higher than those allowed in Europe, according to Public Eye. “Their business model relies on an illegitimate strategy of deliberately lowering the quality of fuels in order to increase their profits,” the report read.

It said companies, among them the Swiss commodity traders Trafigura and Vito, increased their profits at the expense of Africans’ health. While the European Union (EU) has allowed ten parts per millions (ppm) of sulfur in diesel in the continent, the legal limit on sulfur petrol in some African countries like Nigeria is 3,000 ppm. After burning, the sulfur is released into the atmosphere as sulfur dioxide and other particulates that provide a major contributor to respiratory symptoms such as bronchitis and asthma.

According to the report, 20 million people in the Nigerian state of Lagos breathe 13 times more particulate matter than people in London, with dirty fuel being the main reason. This is while Nigeria and some other West African countries produce petroleum with the world’s lowest sulfur levels. They do not have refining capabilities, however, and have to import fuel from Europe.

“Africa could prevent 25,000 premature deaths in 2030 and almost 100,000 premature deaths in 2050” if the export of low-quality fuel is stopped, Public Eye said. It called on African governments “to protect the health of their urban population, reduce car maintenance costs, and spend their health budgets on other pressing health issues.”

“If left unchanged, their practices will kill more and more people across the continent,” the report warned. In response to the allegations, the report said, three of the companies denied any wrongdoing, arguing that they meet the regulatory requirements of the market. Public Eye, however, said that the companies adjusted their blends with no increased costs when Ghana lowered its sulfur content level in 2014.

Presstv