Residents who live near two industrial factories in West Oakland and West Berkeley may suspect that the air they breathe contains higher than average levels of lead and other heavy metals.

Now a new pilot study sponsored by the nonprofit Global Community Monitor will help them find out.

The study involves testing the blood of children ages 1-5 who live within a mile of Custom Alloy Scrap Sales, or CASS, on Poplar Street in West Oakland, and Pacific Steel Casting on Second Street in West Berkeley. The companies have been targeted by environmental groups for pollution issues that are compounded by their proximity to residential neighborhoods.