Particulate matter accumulation on apples and plums: Roads do not represent the greatest threat

Abstract

Particulate matter (PM) is a mixture of solid and liquid substances of organic and inorganic character suspended in air. Plants are used as biological filters of air. However, PM can be deposited on their edible parts, with a negative effect on people’s health. The aim of this study was to document the PM accumulation on apples and plums harvested from orchards located alongside roads with differing amounts of traffic. Plums accumulated more PM than apples. The deposition of PM on apples increased during fruit development and was highest at harvest. The impact of road type, traffic intensity, and distance from the road on PM accumulation on fruit was small. The least PM was adsorbed by apples harvested from an orchard located close to a road with the highest traffic, while in the case of plums, no effect of the road on PM deposition was recorded. The amount of PM accumulated on fruits depended on the species (fruit morphology, harvest period), activities undertaken in the orchard (early pruning exposes fruits to PM, ecological preparations increase fruit viscosity), and sources of pollution other than the roads located close to the orchard. Washing fruits with water removed half of the accumulated PM.