Environmental Pollution Series A, Ecological and Biological最新文献

The biological effects of heavy metal contamination of coniferous forest soils were studied in the A₀₁/A₀₂ layer around a primary smelter in Northern Sweden. Soil concentrations of 17 elements were determined. Smelter-emitted heavy metals were 5 to 75 times higher in the plot closest to the smelter compared with background levels. Despite emission of sulphur no decrease in pH was found.

Bacteria producing acid from maltose, cellobiose, arabinose or xylose and bacteria hydrolysing starch, pectin, xylan or cellulose decreased 8- to 11-fold due to the soil contamination. Chitin hydrolysers were 5 times less abundant at the most polluted site compared with background levels. Soil respiration rate and urease activity decreased by about a factor of 4, but phosphatase activity and mycelial lengths were unaffected by the soil contamination. Soil bacteria showed a sigmoidal response to the log of metal concentration in the soil and were affected at a lower pollution level than the other biological variables in the study.

A multivariate analysis (partial least squares) showed that soil metal contamination and soil pH were the two environmental factors influencing the soil microorganisms.

Sediments from the highly mercury-contaminated Berry's Creek in the Hackensack Meadowlands of New Jersey were brought into the laboratory to investigate the effects of different environmental factors on their release of mercury and its uptake by Fundulus heteroclitus. Sediments were placed in 16 aquaria in which conditions of pH (6 vs 8), salinity (0·3% vs 1·2%), aeration (aerated or unaerated) and stirring (stirred or not stirred) were varied. Mercury analysis was performed on Fundulus heteroclitus from the aquaria. Condition factor of the fish was also monitored. Low oxygen was associated with higher levels of mercury in the fish and with poorer condition. Stirring the sediment did not decrease fish condition, and was associated with lower Hg uptake. The concentration of mercury in the sediments in individual tanks was not related to the uptake by the fish. Monitoring of mercury levels of fish collected from Berry's Creek throughout the year revealed a 5-fold increase during the summer months.

Common tern clutch size, reproductive success and growth of young recorded from an abandoned barge on the Providence River, an area of heavy metal contamination, were equal to, or greater than, from less contaminated areas. Concentrations of copper and zinc were higher in livers of nestling terns from the Providence River than from other, less contaminated, areas. However, concentrations of magnesium, manganese, and iron and the frequency of nickel were equal, or lower, at Providence than other, less contaminated, locations. Among-colony trends in residues of copper, zinc and nickel in prey samples were similar to trends found in nestling livers. Uric acid concentrations in nestling blood were twice as high in the Providence River than another colony and may have resulted from moderate levels of chromium in the diet.

Fly ash was added to a sandy soil and a sandy loam to study its effects on soil microbial respiration. Microbial respiration was reduced with increasing fly ash treatments in the sandy soil, whereas in the sandy loam, a significant depression was only recorded at the highest ash addition for both total and cumulative carbon dioxide evolved. Total carbon dioxide release was actually increased by 3% and 6% ash amendment on the sandy loam. A highly negative correlation was found between respiration and ash treatment for the sandy soil (r = −0·9904, p < 0·005), but not for the sandy loam. Ecological dose 50% (EcD₅₀) values of the sandy soil were smaller than that of the sandy loam for each period. The reasons for this are discussed.

Preliminary sampling of the Caloosahatchee River, which serves as a source of drinking water for the city of Ft Myers, Florida, showed that aldicarb, aldicarb sulphoxide and aldicarb sulphone had contaminated the river. These toxicants are associated with the pesticide Temik. Concentrations of total residue were as high as 17·9 μg litre⁻¹ at one site, but contaminants were never detected in final (treated) drinking water.

Concentrations of only 10 μg litre⁻¹ of aldicarb sulphoxide have significant impacts on the life history characteristics of a common Florida daphnid, Daphnia laevis. We suggest that Temik use in Florida, and perhaps elsewhere, may prove detrimental to the biota of surface water systems.

Over the period 1980–1984, water and fish samples have been routinely analysed for pesticide residues as part of a more general lake and watershed monitoring programme. Water samples were taken from 14 sites in the Hula Valley, close to the main farming areas. Initially, concentrations of various pesticides (such as Parathion and Endosulphan) were high, especially at certain sites, but later, only traces of these chemicals were found even though there has been little reduction in the quantities of pesticides used. During the rainy season some residual pesticides remaining in the soil were washed into the drainage canals at the beginning of the winter floods, but concentrations dropped rapidly, suggesting that either quantities of pesticides in the fields were low, or that they were bound strongly to soil particles. Fish analyses largely comprised cases of deliberate poisoning of Sarotherodon galileaus (St Peter's fish), by Endosulphan and/or Lindane, for illegal fishing purposes. In the past few years, however, the numbers of both suspected fish poisonings and poisoned fish have significantly declined, and analyses now mostly involve spot checks of catches. ‘Baseline’ studies of fish, zooplankton, algae and benthic mussels, as well as water samples, from the lake were also carried out. Pesticide residues were not found in any of these samples. These results suggest that the potential threat to the Kinneret from pesticide residues is at present relatively low. The Kinneret Limnological Laboratory pesticide monitoring programme has been, at least partially, instrumental in reducing pesticide contamination (accidental or otherwise) of water or fish, in the lake and watershed. In the light of possible changes in agricultural practices and water management policies in the north of Israel, however, this programme will be continually updated to avoid any deterioration in the current situation.

The use of acid insoluble residue (AIR) as a marker fraction in the soil is proposed for correcting measurements of the heavy metals: Zn, Cu, Cd and Pb in earthworm samples to eliminate the contribution from soil in the earthworm gut. Five species of earthworm were kept for 15 days on four experimental soils which contained different levels of Zn, Cu, Cd and Pb. Results of heavy metal concentrations in earthworm tissue obtained after calculation using the correction based on AIR content were compared statistically with results obtained by other methods. In the majority of soil/earthworm combinations no significant difference emerged between the calculated results and those obtained after dissection of earthworm samples, suggesting that the correction using AIR content provides a suitable method for estimating levels of heavy metals present in earthworm tissue.

Field evidence for an acid rain effect on lichens at two sites in Northern England is presented. Well established populations of Lobaria pulmonaria on oak, and Sticta limbata on ash trees in remote rural areas were observed to decline to the point of extinction. This was accompanied by bark acidification. Only lichens containing a blue-green algal component and growing in habitats poorly buffered on the acid side were affected. This phenomenon is discussed in the context of general acid rain effects on lichens.