Contamination of soils by metals and metalloids is an important environmental problem in many residential and industrial sites around the world. Lead is a common contaminant, which enters the soil through mining, industrial activities and waste disposal. A range of technologies can be used to remediate soil lead, however most remediation technologies adversely affect the environment and particularly soil biota. We have assessed the efficacy of vermiremediation (the use of earthworms for remediation) to reduce water extractable lead concentrations in soil. Earthworms were introduced to a sandy soil spiked with the common lead minerals cotunnite (PbCl2), cerussite (PbCO3), massicot (PbO) or galena (PbS) at 1000 mg (Pb) kg−1. Lead concentrations in pore water extracted during the experiment were not significantly different in contaminated soil with and without worms. However, concentrations of lead in water from a deionised water extraction (washing) of contaminated soil were significantly lower in soil with earthworms than in soil without. Earthworms accumulated on average (±1 standard deviation) 276 ± 118, 235 ± 66, 241 ± 58 and 40 ± 30 mg kg−1 (dry weight of earthworms) of lead in their bodies, in PbCl2, PbCO3, PbO and PbS-dosed soils, respectively. During the experiment, earthworms lost weight in all contaminated soils, except those containing PbS.

Effect doses (EDs) of metals/metalloids, usually obtained from toxicological experiments are required for developing environmental quality criteria/standards for use in assessment of hazard or risks. However, because in vivo tests are time-consuming, costly and sometimes impossible to conduct, among more than 60 metals/metalloids, there are sufficient data for development of EDs for only approximately 25 metals/metalloids. Hence, it was deemed a challenge to derive EDs for additional metals by use of alternative methods. This study found significant relationships between EDs and physicochemical parameters for twenty-five metals/metalloids. Elements were divided into three classes and then three individual empirical models were developed based on the most relevant parameters for each class. These parameters included log-βn, ΔE0 and Xm²r, respectively (R² = 0.988, 0.839, 0.871, P < 0.01). Those models can satisfactorily predict EDs for another 25 metals/metalloids. Here, these alternative models for deriving thresholds of toxicity that could be used to perform preliminarily, screen-level health assessments for metals are presented.

The transfer of pollutants from chemical fertilizers through food webs within cropland is well documented; however, its impacts on the wild animals that forage on croplands but roost in other locations remain poorly understood. The potential for this cross-ecosystem ‘spillover’ of pollutants is greatest for bats, some of which exploit urban settlements as roosting niches but must travel long distances to reach croplands as foraging niches. Here, we used hairs from a colony of insectivorous bats, Chinese Noctule (Nyctalus plancyi), from an urban area in Southwest China to assess whether exposure to heavy metals/metalloids by the bats varied from 1975 to 2016. Historical changes occurred in hair cadmium (Cd) concentrations in adult females, which was exclusively explained by the regional fertilizer application intensity (FAI), even considering the potential impacts of Cd emissions in urban areas, as indicated by camphor trees (Cinnamomum camphora) near the bats' roosting niche, and the potential impacts of Cd in industrial wastewater, as documented in authorized databases. Therefore, the data from this bat colony, as urban dwellers, indicates Cd accumulation and cross-ecosystem transfer from rural croplands to an urban area.

Uranium mining is an environmental concern because of runoff and the potential for toxic effects on the biota. To investigate uranium toxicity to freshwater invertebrates, we conducted a 96-h acute toxicity test to determine lethal concentrations (testing concentrations up to 262 mg L⁻¹) for three stream invertebrates: a shredder caddisfly, Schizopelex festiva Rambur (Trichoptera, Sericostomatidae); a detritivorous isopod, Proasellus sp. (Isopoda, Asellidae); and a scraper gastropod, Theodoxus fluviatilis (Gastropoda, Neritidae). Next, we ran a chronic-toxicity test with the most tolerant species (S. festiva) to assess if uranium concentrations found in some local streams (up to 25 μg L⁻¹) affect feeding, growth and respiration rates. Finally, we investigated whether S. festiva takes up uranium from the water and/or from ingested food. In the acute test, S. festiva survived in all uranium concentrations tested. LC₅₀-96-h for Proasellus sp and T. fluviatilis were 142 mg L⁻¹ and 24 mg L⁻¹, respectively. Specimens of S. festiva exposed to 25 μg L⁻¹ had 47% reduced growth compared with specimens under control conditions (21.5 ± 2.9 vs. 40.6 ± 4.9 μg of mass increase animal⁻¹·day⁻¹). Respiration rates (0.40 ± 0.03 μg O₂·h⁻¹·mg animal⁻¹) and consumption rates (0.54 ± 0.05 μg μg animal⁻¹·day⁻¹; means ± SE) did not differ between treatments. Under laboratory conditions S. festiva accumulated uranium from both the water and the ingested food. Our results indicate that uranium can be less toxic than other metals or metalloids produced by mining activities. However, even at the low concentrations observed in streams affected by abandoned mines, uranium can impair physiological processes, is bioaccumulated, and is potentially transferred through food webs.

Three sub-basins of the Seine River (France) under contrasted land uses (i.e., forested, agricultural, and urban) have been investigated in order to assess the origin and seasonal variation of trace metals, and evaluate their geochemical background and dynamics. Our results highlight a high anthropogenic impact on all elements for both the dissolved and particulate fractions. The main source for each element in the dissolved phase was determined and shows that transition and post-transition metals mainly originate from forested areas, while alkali and alkaline earth elements, metalloids, and halogens rather originate from agricultural land use. Conversely, for the particulate phase, most of the elements cannot be associated with a specific land use. Seasonal variation of elements was assessed according to the forested and agricultural land uses, and geochemical backgrounds were determined using average export rates, highlighting that the geochemical background for the forested land use is higher than the agricultural one for most of the elements. Finally, to confirm those results, Zn dynamics in the three characteristic sub-basins and between the different land uses was investigated using a combination of Zn speciation, Zn isotopic ratio, and Zn export rates.

An evaluation of the concentration of metals in terrestrial and aquatic environments near Artigas Antarctic Scientific Base was assessed. Granulometric characteristics, total organic matter content, concentration of metals (Cd, Cr, Cu, Mn, Ni, Pb and Zn) and metalloid (As) in soil, marine and freshwater sediments were determined. The geoaccumulation index (Igeo) was used in order to analyse the contamination magnitude. Samples were collected in summer 2015–2016 covering 31 sampling stations; 15 terrestrial/soil stations (T0–T14) were placed considering the distribution of Artigas Base buildings and the septic tanks’ location. Eleven freshwater stations were placed along the three meltwater streams near Artigas Base (S0–S10), and two in Uruguay Lake (L1 and L2). Finally, three marine stations in Maxwell Bay were placed one near the Artigas Base (AB) and two far from it in North Cove (NC1, NC2). Some of the terrestrial stations (T2, T10, T11 and T13) presented the highest concentration of metals and Igeo values, which was associated to anthropic activities. Highest metal levels were related to fuel storage and handling, but also, with sewage release and the presence of old leaded paint residues. These polluted sites were limited to a restricted area of Artigas Base, not affecting surrounding environments. Concentrations of the analysed metals in unpolluted sites had the same order of magnitude recorded in other unpolluted areas of the Fildes Peninsula and other Antarctic regions.