Washington ? A new Environmental Protection Agency study concludes that children who repeatedly come in contact with playground equipment and decks made of arsenic-treated wood face increased risk of developing cancer.

The study suggests the risk to children is considerably greater than EPA officials indicated last year in announcing the products were being taken off the market. While manufacturers have agreed to stop producing arsenic-treated wood products beginning in 2004, such wood remains in many public playgrounds and back yards.

The preliminary findings released Thursday show that 90 percent of children repeatedly exposed to arsenic-treated wood face a greater than one in 1 million risk of cancer — the EPA’s historic threshold of concern about the effects of toxic chemicals.

The problem appears to be greater in the warmer climates of southern states, where children tend to spend more time playing outdoors. There, 10 percent of all children face a cancer risk that is 100 times higher than children in the general population, according to a review of the EPA data by the Environmental Working Group.

EPA officials cautioned that the findings are preliminary and are subject to review next month by the agency’s Scientific Advisory Panel.

But officials stressed that people should take precautions, such as washing their hands after coming into contact with arsenic-laced wood and never placing food directly on a deck or outdoor table surface.