Monitoring of polycyclic aromatic hydrocarbons using ‘moss bags’: Bioaccumulation and responses of antioxidant enzymes in Fontinalis antipyretica Hedw.

The accumulation of polycyclic aromatic hydrocarbons (PAHs) and responses of antioxidant enzymes were studied in an aquatic moss, Fontinalis antipyretica (Hedw.) transplanted around a city harbor. Glass fiber bags containing Fontinalis antipyretica (‘moss bags’) were transplanted at five sites on Lake Kallavesi of Finland in summer. Three sites were located south (downstream) and near (0.2–4 km) to the Kuopio city harbor area, and two sites which were located north (upstream) and far (7–10.5 km) from the harbor served as reference sites. PAH accumulation and the responses of the activities of antioxidant enzymes were determined in the transplanted moss following 35 days of exposure to PAHs contained in the lake water. Significantly higher levels of total PAHs in water (mean t S.D.; 41.6 ± 4.7 ng L−1) and moss tissue (48.2 ± 2.2 ng g−1 dry weight) were observed at the sites close to the harbor compared to the corresponding values (water, total PAHs = 6.7 t 1.6 ng L−1; moss, total PAHs = 5.4 ± 0.9 ng g−1 dry weight) obtained from the reference sites. Compared to that observed at reference sites, higher activities of antioxidant enzymes (peroxidase, 2-fold higher; ascorbate peroxidase, 3 fold higher; and superoxide dismutase, 70% higher) that detoxify partially reduced and activated forms of oxygen were observed in moss transplanted near the harbor. This study introduces a novel approach to investigate the cause-effect relationship between bioaccumulation of aquatic pollutants and the biochemical responses in organisms following exposure to such pollutants in a field setting.