Environmental Pollution Series A, Ecological and Biological最新文献

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.

Laboratory-bred Sminthopsis macroura, small (20–30 g) insectivorous marsupials, ingesting quickly (in less than 4 min) a large dose (80–100 mg kg⁻¹ body weight) of monocrotophos [1-[N-methylcarbamoyl)propyl-en-2-yl dimethyl phosphate], died within 30 min with cholinesterase (ChE) activity in their brain tissues inhibited by 66–69%; those that had ingested a much smaller dietary dose (2 mg kg⁻¹ body weight) at intervals during 18 days survived despite a higher ChE inhibition (92% on the 18th day). Notomys alexis and N. mitchelli, two species of small (30–50 g) rodents native to Australia, survived for 5 days on a diet of hulled millet containing 668 mg kg⁻¹ monocrotophos despite a 64% and 58% inhibition of ChE activity by the 5th day and a drastic reduction in food consumption reflected by a 14% and 12% loss of body weight respectively. These responses are discussed in terms of their effects on toxicity studies.

Ten 80-year-old spruce Picea abies trees from a forest district on the south side of the Taunus mountain range adjacent to the densely populated Rhine-Main area were analysed for their protein and amino acid metabolism.

The quantities of SDS-soluble proteins in the youngest needles decreased slightly with increasing defoliation of the trees, but SDS-protein patterns remained constant. In the youngest needles, however, proteinogenous amino acids increased severalfold with increasing needle loss. Arginine, threonine, isoleucine, alanine, tyrosine, lysine, histidine, leucine, methionine,and serine increased about 300%, valine and glycine about 250%. On the other hand, the contents in phenylalanine decreased about 60% and, in cysteic acid, about 22%. Chlorophyll contents in the youngest needles were relatively constant (no yellow needles present). The amount of dry matter increased slightly.

The rise in amino acid concentrations which wer observed is severalfold higher than that estimated 10 years ago in areas polluted by gaseous SO₂. We suggest that the increasing contents of amino acids are attributable to high amounts of ammonia which have accumulated in the forest soil.

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.

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.