Women in Los Angeles County are becoming less healthy, and their well-being is expected to decline further because of the slumping economy and other factors that deter access to better food and exercise, according to a sweeping study released Wednesday.

The survey of more than 3,500 women, conducted by the county Department of Public Health, studied physical, mental and emotional aspects of health care and found troubling trends that raise questions about the effectiveness of social services.

An estimated 40 percent of adult women are at risk for heart disease, the study found, although that number soars to more than 52 percent for black women. And about 53 percent of white women say they exercise regularly, compared with 49 percent for women overall.

“There are terrible discrepancies,” said Dr. Jonathan Fielding, who heads the department. “Women often make the health care decisions for their families and are the primary caregivers when a family member falls ill. Therefore, the health of women affects not only the individual, but her family and her community.”