anthropogenic 203 aquatic 179 sludge 169 wastewater 126 terrestrial 98 built environment 50 fresh water 46 low salinity 41 lentic 35 lacustrine 31 medium temperature 29 soil 21 very low temperature 20 sewage 16 anaerobic 9 rhizosphere 6 host-associated 6 littoral 6 marine 6 plant host 6 wetland 4 groundwater 4 mangrove 4 brackish water 4 estuary 4 medium salinity 4 subsurface 4 stream 3 ice 3 forest 3 agriculture 2 low temperature 2 tundra 2 grassland 1 contaminated 1 fluvial 1 cropland 1 lotic 1