Evernia Goes to School: Bioaccumulation of Heavy Metals and Photosynthetic Performance in Lichen Transplants Exposed Indoors and Outdoors in Public and Private Environments.

Luca Paoli,Katarína Kresáňová,Caterina Maccelli,Zuzana Fačkovcová,Stefano Loppi,Anna Guttová

doi:10.3390/plants8050125

Abstract

Recently indoor air quality (IAQ) has become a key issue, especially in schools, where children spend most of the day. Only in a few cases IAQ was investigated using lichens as biomonitors. During autumn 2017, lichens (Evernia prunastri) were exposed for two months indoors and outdoors in public (schools) and private (dwellings) environments, in both rural and urban areas of Slovakia. The bioaccumulation of selected elements and the physiological status of the samples were considered. The content of heavy metals increased in samples exposed outdoors for 11 out of 12 elements (Al, As, Cd, Cr, Cu, Fe, Pb, S, Sb, V and Zn, but not Ca) in the urban area and for 5 (As, Cd, Cu, Pb and Sb) in the rural area. Indoor concentrations were overall similar, both in rural and urban buildings, independently of the outdoor conditions. An indoor accumulation occurred only for Cd, Cu and Pb. An indoor origin was suggested for Cd, while for Cu and Pb, outdoor penetration (car traffic) is the likely cause of indoor values. Indoor exposed lichens maintained their vitality (as reflected by chlorophyll a fluorescence emission). This latter result further supports the use of lichen biomonitoring as a suitable method for assessing IAQ.

Highlights

The quality of the air that we constantly breathe is more relevant for our health than we think, and recent estimates showed that 92% of the world’s population lives in places with air pollution levels exceeding WHO guidelines [1]
Higher outdoor concentrations were measured in the urban area, indoor concentrations were on the whole similar both in rural and urban schools and houses, irrespective of the outdoor conditions
We focused our attention on heavy metal depositions and assumed that the content of elements in lichen exposed andquality indoors(IAQ)

Summary

Introduction

The quality of the air that we constantly breathe is more relevant for our health than we think, and recent estimates showed that 92% of the world’s population (urban and rural) lives in places with air pollution levels exceeding WHO guidelines [1]. We inevitably inhale the surrounding air, with airborne compounds coming in contact with our cells and impacting our life and health. Most people spend over 85% of their time within indoor environments, such as schools, dwellings, transports, shops, restaurants, offices and working places in general. The quality of the air in indoor environments is of paramount importance for our personal well-being and comfort [3].

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Conclusion