© FORESTPATH/SHUTTERSTOCK
In April 2009, epidemiologist Marc Weisskopf of the Harvard T.H. Chan School of Public Health and colleagues came across a puzzling correlation as they were looking for links between the neurodegenerative disease known as amyotrophic lateral sclerosis (ALS) and exposure to 11 different chemical classes. They analyzed mortality data from a sample of more than 1 million people involved in the American Cancer Society’s Cancer Prevention Study II. While the researchers found little evidence of a link between ALS and most of the chemicals they examined, one did raise a red flag: formaldehyde, a compound commonly used in funeral homes and medical laboratories. Those participants who reported being regularly exposed to the chemical were more than twice as likely to die from ALS, compared to ...
