Activity based sampling was done during some of the driest times of the year. Wouldn’t the amount of airborne asbestos be lower most of the time?
EPA believes conditions during testing probably do not overestimate asbestos exposure. The activity-based sampling was conducted in summer, when people are more likely to come into contact with Swift Creek sediments. During the sampling event, the dredge piles were still moist from recent rain. Under dryer conditions, we might expect more asbestos to become airborne. Under wetter conditions, we might expect less asbestos to become airborne during testing, but because moist sediments can stick to clothes and shoes, more asbestos could be tracked into cars or buildings, resulting in possible additional exposure.
