Environmental Pollution Series A, Ecological and Biological最新文献

A sediment core from Lake Lippajärvi, sampled by freezing it in situ, was investigated. The sedimentary sequence was dated using the ¹³⁷Cs method and the ²¹⁰Pb content of the core was also determined. It seems that, during the recent history of the lake, increasing eutrophication is the main factor controlling fluctuations in lake ecosystems. This increase is clearly reflected in the changes in the diatom stratigraphy of the core investigated. Sequential extraction analysis was performed for speciation of elements in the sediment. Ammonium acetate and hydroxylammonium chloride plus acetic acid were used as extractants; acid digestion and extraction by NaClO and NaDDTC/MIBK were also performed.

An increase in sedimentation rate is apparent for the upper part of the lithostratigraphy of Lake Lippajärvi. The increased nutrient load and heavy metal input have led to cultural eutrophication and pollution effects in the lake, and black bands of Fe monosulphides have emerged in sediments as a sign of oxygen deficit in the hypolimnion. The eutrophication of Lake Lippajärvi is also accompanied by biogeochemical cycles and limnogeochemical processes apparently responsible for the leaching of chemical elements from sediments and their subsequent redeposition in more loosely bound forms. Fe has been redeposited mainly as Fe oxyhydroxides and monosulphides, and Cu and Zn also seem to be associated with these precipitates. Ca, Mn and Zn are present to relatively large degrees as very loosely bound and sorbed forms. Fe, Mn, Cu and Zn are also associated with sulphides, and Fe and Cu with biogenic matter. There is a clear difference between man-made airborne forms of Pb and natural mineral-bound forms in the sediment column of the lake. In the polluted part of the investigated lithostratigraphy, Pb is mainly present in loosely bound reducible forms. Al and Si also seem to show leaching and redeposition in the sediments of Lake Lippajärvi.

This paper provides information on the effect of automobile exhaust pollution on wild dicotyledonous plants growing along a road carrying dense traffic. There is a close correlation between the distance of the plants from the roadside and acceleration in peroxidase and catalase activities. These two physiological characteristics may serve as indicators of the levels of automobile exhaust pollution.

Lead concentrations were determined in sediment and tadpoles of bullfrogs Rana catesbeiana and green frogs R. clamitans from drainages along highways with different daily average traffic volumes (range, 4272 to 108 800 vehicles day⁻¹) and from ponds ≥ 0·4 km from the nearest highway. Lead concentrations (mg kg⁻¹ dry weight) in sediment (7·8 to 940) were usually greater (4–5 times) than those in the tadpoles (bullfrog, 0·07 to 270; green frog, 0·90 to 240 mg kg⁻¹). Lead concentrations in sediment (r = 0·63) and in both species of tadpoles (bullfrog, r = 0·69; green frog, r = 0·57) were positively correlated with average daily traffic volume. Lead concentrations in both species of tadpoles (bullfrog, r = 0·76; green frog, r = 0·75) were also positively correlated with lead concentrations in sediment. At sites where both bullfrog and green frog tadpoles were collected, lead concentrations in the two species were closely related (r = 0·84). Lead concentrations in tadpoles living near highways may contribute to the elevated lead levels reported in wildlife that are potential tadpole predators. Dietary lead concentrations similar to those in our tadpoles have been associated with physiological and reproductive effects in some species of birds and mammals. However, additional data are needed to determine the hazards to predators of lead concentrations in tadpoles.

Exhaust emissions from automobiles have been frequently connected with a new type of forest disease which is described for conifers and, more recently, also for deciduous trees. The use of the catalytic converter for pollution control and, consequently, as a remedy for forest decline, has been extensively advocated. No data are yet available on the efficiency of catalytic devices with respect to the toxicity of exhaust emissions. We have therefore studied this question in Norway spruce Picea abies (L.) Karst. under defined conditions. The efficiency of the catalyst was tested with concentrations of exhaust emissions which produced significant injuries within a limited period of time. A fast reduction of photosynthetic capacity and impairment of stomatal regulation was observed after a fumigation of only 15 min without a catalytic converter, followed by changes in colour and, finally, by needle dropping. During the early stages, buds were not injured and developed into healthy shoots. Consequently, symptoms of an inner browning and needle dropping could be mimicked. In the presence of a catalytic converter, essentially no damage to spruce could be observed under analogous conditions.

The effect of O₃ and SO₂ on leaf diffusive resistance (LDR) of yellow poplar seedlings was studied at 40% and 80% humidity. LDR was measured at 0800, 0900, 1100, 1400 and 1600 h on seedlings fumigated from 0900 h until 1400 h each day for five consecutive days. Fumigation treatments were control, 0·15 μl litre⁻¹ O₃, 0·25 μl litre⁻¹ SO₂ and 0·15 μl litre⁻¹ O₃ + 0·25 μl litre⁻¹ SO₂. No change in daily LDR response was observed for the seedlings at 40% humidity. At 80% humidity, daily LDR response of seedlings in all four treatments changed significantly over the 5 days of the experiment. The range of the LDR values and the daily response curves both changed. The higher humidity apparently caused the stomata to open so that more pollutants could enter the leaves. The pollutants then interacted with the leaf cells and modified the stomatal response.

Two-month-old chilbil Holoptelea integrifolia plants were exposed to 0·06, 0·1 and 0·8 μl litre⁻¹ sulphur dioxide (SO₂) for 4 h in a continuous flow exposure chamber. Symptoms mapped 48 h after exposure indicated no visible injury. The biochemical changes included accumulation of free sugars, especially reducing sugars in tissue associated with depletion of starch, and enhanced acid phosphatase in exposed plants. Constancy in chlorophyll level and rate of CO₂ fixation, together with the absence of visual symptoms, suggest the resistant nature of the chilbil tree.

Two-day-old plants of spring barley Hordeum vulgare cv Patty were exposed to 100 nl litre⁻¹ SO₂ and 100 nl litre⁻¹ NO₂ singly and in combination for 20 days. Exposure to SO₂ was found to reduce the root dry weight significantly but total shoot weight was relatively less affected. NO₂ applied on its own had very little effect on growth, but in combination with SO₂ it caused highly significant reductions in almost all the growth parameters measured. In another study plants of the same age were exposed for 2 weeks to mixtures of SO₂ and NO₂, ranging in concentration from 40 to 140 nl litre⁻¹ of each gas, and growth inhibitions were found to increase with increasing dose. It is concluded that the effects of SO₂ and No₂ applied together are greater than would be predicted from their individual effects and that the dose-response curve could be used in a predictive manner for a given set of conditions.

A laboratory-scale study was performed to determine the biodegradability of glucose in the presence of cyanide and phenol. The concentration of chemicals was maintained at a low level which would normally be experienced in natural streams receiving industrial wastes. A continuously fed, complete-mix reactor was utilised. The system was totally closed and included traps to separate volatilised cyanide from the products resulting from hydrolysis. For several steady-state conditions the influent and effluent water quality with respect to micro-organism, glucose, cyanide, phenol, ammonia, and total nitrogen concentration was determined. Influent waste quality varied (i.e., different concentrations of feed chemicals) for different steady-states.

Biological degradation kinetics for total organic carbon, cyanide, and phenol were developed. The rates were found to be related to temperature and the concentration of the different chemicals in the solution. The system sensitivity with respect to cyanide, phenol, and organic carbon levels was discussed. The results indicated that statistically developed relationships for the biodegradation of glucose, cyanide and phenol can adequately represent the degradation rates at low concentrations of cyanide and phenol (cyanide < 4·00 mg litre⁻¹ and phenol < 1·40 mg litre⁻¹).