Impact of biomass combustion on occurrence and distribution of aromatic hydrocarbons in apples

Particulate Matter Accumulation on Apples and Plums: Roads Do Not Represent the Greatest Threat

“…The orchard adjacent to the local road was managed organically, with the cultivation of a large number of apple varieties harvested on different dates (from mid-September to late October) and the application of plant protective agents authorised for use in organic production, which often increase the surface stickiness of the fruits. Late harvest may also result in the accumulation of airborne pollutants created by domestic heating, which has already been recorded in apple skins [11,15]. Furthermore, in the present study, the accumulation of PM on apple fruits was also not affected by distance from the road.…”

“…However, in all the examined locations, the fruits sampled in October accumulated a significantly higher amount of PM deposited in wax ( W PM). It can therefore be assumed that the proportion of lipophilic pollutants increased, e.g., polycyclic aromatic hydrocarbons from domestic heating and most likely vehicles operating within orchards and on surrounding roads [15,31]. The share of PM embedded in wax was highest in apples harvested in the orchard near the national road, which confirms that although transport was not the main source of PM in this study, at this location its contribution was greater than in other orchards.…”

“…This also applies to pollutants carried by PM, e.g., Fe and Zn are harder to wash off than Cd and Pb because they tend to penetrate the plant surface more deeply [25]. Polycyclic aromatic hydrocarbons are particularly difficult to remove from fruit surfaces because their lipophilic nature means that they are embedded almost exclusively in the epicarp, especially wax [15]. Schreck et al [17] and De Temmerman et al [16] demonstrated that washing removes a maximum of 25% of total Pb-rich and Cd-rich particles, which might suggest that a significant amount of PM is deposited in the cuticular wax.…”

“…Schreck et al [17] and De Temmerman et al [16] demonstrated that washing removes a maximum of 25% of total Pb-rich and Cd-rich particles, which might suggest that a significant amount of PM is deposited in the cuticular wax. Fortunately, according to Paris et al [15] airborne pollution is rarely transferred to the mesocarp, because skin is an efficient hydrophobic protective barrier. Peeling removes most of the cumulative pollution by fruits from the air [66], but this reduces their nutritional value.…”

“…Furthermore, even if PM is of a relatively low concentration, there is a possibility that pollutants may accumulate in the edible parts of plants beyond safe levels if the exposure time is extended [13]. Relatively high concentrations of polycyclic aromatic hydrocarbons, which easily accumulate in the hydrophobic surface layers of plants [11,15], and trace elements, including heavy metals less bioavailable in soils [5,13,[16][17][18], have been recorded in the edible parts of vegetables and fruits. Where this is the case, fruits in case of which high atmospheric deposition has been determined as the principal accumulation pathway of pollutants could be great source of harmful substances for humans, comparable to inhalation and dermal contact.…”