The association between indoor black carbon levels and bacterial communities measured with Hedera helix

Abstract

Air pollution is a serious problem since millions of people die prematurely from illnesses attributed to air pollution. Further, since most of our time is spent in the indoor environment, the focus will be on indoor air quality. Here the focus is on black carbon (BC) and was measured with the H. helix. These particles might be associated with changes in microbial diversity and the hypothesis is that differences in indoor BC levels result in a change in bacterial diversity of the H. helix. First, no significant correlation (p=0.15) was found between the particle area on the leaves and an indoor BC aethalometer measurement. However, when using a mixed model with the percentage of residential area significance was reached (p=0.03). Second, the association between the particle area and bacterial alpha-diversity was also not significant (Chao1 p=0.38, ASV richness p=0.38, Shannon-Wiener index p=0.76, Simpson index p=0.88). The PERMANOVA analysis also showed no association between the beta-diversity (Bray-Curtis dissimilarity matrix) and the particle area (p=0.59) but nearly half the variation was explained by the particle area (R2=0.48). From these results, we can conclude that the biomonitoring model can measure indoor BC, but more research is necessary to confirm the use of the model. Further, no association was found between the diversity and particle area, but more power is required to obtain significant results. However, it is interesting to further investigate the association between BC and microbial diversity.