WASHINGTON (AP) — After more than 40 years of study, the federal government said Monday it has no evidence that the anti-bacterial chemicals used in countless common soaps and washes help prevent the spread of germs, and it is reviewing research suggesting they may pose health risks. Regulators at the Food and Drug Administration said they are revisiting the safety of chemicals such as triclosan in light of recent studies that suggest the substances can interfere with hormone levels and spur the growth of drug-resistant bacteria. The government's preliminary ruling lends new support to outside researchers who have long argued that the chemicals are, at best, ineffective and at worst, a threat to public health.