Washington (AFP) – Back in 2006, US National Guard sergeant Heath Robinson oversaw the burning of waste at a military base in Iraq. Fourteen years later, he died of lung cancer, leaving his family to advocate for veterans like him who were exposed to toxic fumes while in uniform. These so-called burn pits have been commonly used by the US military in post-September 11 conflicts, and are lit to get rid of everything from plastic bottles to human waste to old tires — all incinerated with the aid of jet fuel. But the fumes from these open fires are now suspected of causing a range of illnesses …