The Food and Drug Administration is setting a new limit on the level of arsenic allowed in apple juice. The move comes after more than a year of public pressure from groups that worried about the contaminant's effects on children. Studies showed that apple juice contained very low levels of arsenic, a cancer-causing agent found in water, soil and pesticides. The FDA has monitored the arsenic levels in juice for decades claiming that the levels were not dangerous to consumers. But now, the agency has limited the amount of the contaminant in apple juice to the same level permitted in drinking water.