A federally funded study has found “a strong association” between imported wallboard made in China and metal corrosion in U.S. homes in which the drywall has been installed, the Consumer Product Safety Commission says. Preliminary studies of corrosion in electrical and fire-safety equipment also support that finding, says CPSC, which commissioned the studies. But no definitive tie has been found yet between the drywall and health problems that home owners have reported, which include asthma attacks, headaches and bloody noses. CPSC, which released the findings on Nov. 23, has received 2,091 reports from 32 states, the District of Columbia and
Arch dams, classically curved monoliths situated in narrow valleys, are not as common as other types of dams, such as embankment dams and gravity dams. ENR takes a look at some of the biggest arch dams in the world, both completed and under construction.