The amount of environmental exposure to polycyclic aromatic hydrocarbons, or PAH for short, is strongly linked to a person's risk of developing rheumatoid arthritis, suggests research. These chemicals, formed from the burning of coal, oil, gas, wood, or tobacco as well as the flame grilling of meat and other foods, also seem to account for most of smoking's impact on risk of the disease, the findings indicate. The researchers drew on the U.S. National Health and Nutrition Examination Survey (NHANES) between 2007 and 2016. NHANES evaluates a wide variety of toxicants, along with data related to health, nutrition, behaviors and...