Microbial indicators of heavy metal contamination in urban and rural soils

• Published in: Chemosphere (Oxford) 2006-06, Vol.63 (11), p.1942-1952
• Main Authors: Yang, Yuangen, Campbell, C.D., Clark, L., Cameron, C.M., Paterson, E.
• Format: Article
• Language: English
• Subjects: Analysis methods; Animal, plant and microbial ecology; Applied ecology; Applied sciences; Bioavailability, catabolic, diversity metals; biological activity in soil; Biological and medical sciences; Biological Availability; Carbon - metabolism; Chemistry, Physical - methods; Cities; community ecology; community level physiological profiles; copper; Earth sciences; Earth, ocean, space; Ecotoxicology, biological effects of pollution; Engineering and environment geology. Geothermics; Environmental Monitoring - methods; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; heavy metals; Hydroxylamine - chemistry; lead; Lead - analysis; Lead - isolation & purification; Metals, Heavy - analysis; Metals, Heavy - pharmacokinetics; Metals, Heavy - toxicity; microbial physiology; nickel; Physiological profiles; polluted soils; Pollution; Pollution, environment geology; rural areas; Rural Population; rural soils; Sequential extraction; Soil; Soil and sediments pollution; Soil Microbiology; soil microorganisms; Soil Pollutants - analysis; soil pollution; soil respiration; soil toxicity; Terrestrial environment, soil, air; urban soils; zinc
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2005.10.009

Urban soils and especially their microbiology have been a neglected area of study. In this paper, we report on microbial properties of urban soils compared to rural soils of similar lithogenic origin in the vicinity of Aberdeen city. Significant differences in basal respiration rates, microbial biomass and ecophysiological parameters were found in urban soils compared to rural soils. Analysis of community level physiological profiles (CLPP) of micro-organisms showed they consumed C sources faster in urban soils to maintain the same level activity as those in rural soils. Cu, Pb, Zn and Ni were the principal elements that had accumulated in urban soils compared with their rural counterparts with Pb being the most significant metal to distinguish urban soils from rural soils. Sequential extraction showed the final residue after extraction was normally the highest proportion except for Pb, for which the hydroxylamine-hydrochloride extractable Pb was the largest part. Acetic acid extractable fraction of Cd, Cu, Ni, Pb and Zn were higher in urban soils and aqua regia extractable fraction were lower suggesting an elevated availability of heavy metals in urban soils. Correlation analyses between different microbial indicators (basal respiration, biomass-C, and sole C source tests) and heavy metal fractions indicated that basal respiration was negatively correlated with soil Cd, Cu, Ni and Zn inputs while soil microbial biomass was only significantly correlated with Pb. However, both exchangeable and iron- and manganese-bound Ni fractions were mostly responsible for shift of the soil microbial community level physiological profiles (sole C source tests). These data suggest soil microbial indicators can be useful indicators of pollutant heavy metal stress on the health of urban soils.