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Macrophyta are the initial link introducing toxic mercury to the trophic chain. Research was carried out at 24 stations located within the Polish coastal zone of the Southern Baltic, in the years 2006-2012. Fifteen taxa were collected, belonging to four phyla: green algae (Chlorophyta), brown algae (Phaeophyta), red algae (Rhodophyta) and flowering vascular plants (Angiospermophyta), and total mercury concentrations were ascertained. The urbanisation of the coastal zone has influenced the rise in Hg concentrations in macroalgae, and the inflow of contaminants from the river drainage area has contributed to an increase in metal concentration in vascular plants. At the outlets of rivers possessing the largest drainage areas in the Baltic (the Vistula and the Oder), no increases in mercury concentration were observed in macrophyta. Increase in environmental quality and a prolonged vegetative season results in the growing coverage of algae on the seabed and in consequence leads to rapid introduction of contemporary mercury and Hg deposited to sediments over the past decades into the trophic chain. Thriving phytobenthos was found to affect faster integration of Hg into the trophic web.

In Mediterranean seas and coastal zones, rivers can be the main source of mercury (Hg). Catchment management therefore affects the load of Hg reaching the sea with surface runoff. The major freshwater inflows to the Baltic Sea consist of large rivers. However, their systems are complex and identification of factors affecting the outflow of Hg from its catchments is difficult. For this reason, a study into the impact of watershed land use and season on mercury biogeochemistry and transport in rivers was performed along two small rivers which may be considered typical of the southern Baltic region. Neither of these rivers are currently impacted by industrial effluents, thus allowing assessment of the influence of catchment terrain and season on Hg geochemistry. The study was performed between June 2008 and May 2009 at 13 sampling points situated at different terrain types within the catchments (forest, wetland, agriculture and urban). Hg analyses were conducted by CVAFS. Arable land erosion was found to be an important source of Hg to the aquatic system, similar to urban areas. Furthermore, inflows of untreated storm water discharge resulted in a fivefold increase of Hg concentration in the rivers. The highest Hg concentration in the urban runoff was observed with the greatest amount of precipitation during summer. Moderate rainfalls enhance the inflow of bioavailable dissolved mercury into water bodies. Despite the lack of industrial effluents entering the rivers directly, the sub-catchments with anthropogenic land use were important sources of Hg in the rivers. This was caused by elution of metal, deposited in soils over the past decades, into the rivers. The obtained results are especially important in the light of recent environmental conscience regulations, enforcing the decrease of pollution by Baltic countries.

B. edulis, collected from 33 forested or woodland sites across Poland over 25 years since 1995, were analysed for radiocaesium. The results (137Cs activity range: 25 to 10,000 Bq kg-1 dry weight) provide a good indication of artificial radioactivity in this food material. The relatively higher levels detected in the earlier years, mostly in easterly location, is consistent with depositions from the projected Chernobyl incident (1986) fallout plumes. Nevertheless, the 137Cs concentrations during 1995–2010 were, on average, higher than those reported by other studies for Polish B. edulis over the period 1986–1994. The data concurs with the general hypothesis and observations that deposited 137Cs permeates slowly over time to deeper soil horizons which host the mycelial networks. This delay in availability shows that (apart from hotspots) higher contamination of fruiting bodies occurred around 10 to 20 years after the incident. Local consumers and recreational mushroomers were undoubtedly exposed, although reported 137Cs concentrations suggest that serious breaches of regulated levels were uncommon.

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A study on 137Cs pollution and activity concentrations of 40K in mushrooms of the genera Cortinarius, Leccinum, Russula, Tricholoma, Tylopilus, and Xerocomus from two neighboring regions in southwest China in 2010–2013 revealed different patterns of pollution with 137Cs, which seemed to be highly dependent on climate conditions. Tricholoma matsutake was collected in Yunnan before and after the Fukushima Dai-ichi nuclear accident and showed similar contamination with 137Cs. Mushrooms from the elevation of 2800–3480 m above sea level on the east slope of Minya Konka and forest topsoil showed higher contamination with 137Cs than mushrooms from the highlands of Yunnan. In detail, the activity concentration of 137Cs in caps of mushrooms from Minya Konka were in the range 62 ± 6–280 ± 150 Bq kg−1 dry biomass and from Yunnan at < 4.4–83 ± 3 Bq kg−1 dry biomass. The climate in the region of the Minya Konka is much colder than in Yunnan, which seems to favor deposition of 137Cs at higher altitudes from global atmospheric circulation. The activity concentration of 40K in mushrooms and soils highly exceeded that of 137Cs. The assessed annual effective doses for 137Cs in 1 kg of consumed mushrooms of the genera Leccinum and Xerocomus in Yunnan were low, i.e., in the range < 0.0043–0.049 ± 0.004 μSv, while those for 40K were 0.26 ± 0.02–0.81 ± 0.09 μSv.

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