Articles containing the keyword 'toxicity'

At immediate surroundings of a fiberglass plant in Central Sweden, vegetation shows toxicity symptoms. Soils and birch (Betula pendula Roth) leaves were sampled. The soil was analysed for water soluble and organic bound boron, carbon, nitrogen, and pH. Vegetation was analysed for total boron. Both fractions of boron in the soils increased towards the factory. Organic bound boron increased irregularly because of its strong correlation to carbon content which varied in the area. The C/N ratio increased nearer the industry due to the harmful effect of boron on the decomposition of organic matter. No relation between pH and the distance from the emission source was visible, but B/C ratio was found to increase with increasing pH of the soil. Boron levels in birch leaves were elevated very much close to the factory. The geographical distribution of high levels of boron in birch, corresponded well with high values in soils, and also with the main wind directions. The limit values for visible injury on birch were found to be around 5 ppm of water-soluble boron in soil and around 200 ppm in leaves.

• Eriksson, E-mail: je@mm.unknown
• Bergholm, E-mail: jb@mm.unknown
• Kvist, E-mail: kk@mm.unknown

The apparent toxicity of soil-incorporated monuron, picloram, CDEC, EPTC, CDAA, and sesone to young Pinus resinosa Ait. seedlings was studied over a temperature range of 10–30 °C in growth chambers. The herbicides were first applied to the surface of autoclaved soil at 1 1b/A and later mixed into the soil. Thereafter pine seeds were planted and subsequent seedling development was studied. The effect of CDEC, EPTC, CDAA, and sesone were also studied at dosages of 2 and 3 1b/A (soil surface basis).

Under the conditions of this study, picloram and monuron were persistent in the soil and toxic to pine seedlings, whereas CDEC, EPTC, CDAA, and sesone appeared to be non-toxic. However, the apparent lack of phytotoxicity of the latter group apparently was caused largely by lack of activation of sesone by autoclaving soil and large losses from the soil of CDEC, EPTC, and CDAA even before seeds were planted.

High toxicity of picloram and monuron was showed by reductions in seedling survival, total dry weight increment of plants, and dry weight increment of surviving seedlings. Various temperature regimes greatly affected growth of herbicide treated plants and controls. In control plants both high and low temperatures adversely affected seedling survival and dry weight more than shoot growth. Temperature extremes generally inhibited root growth more than shoot growth. The high temperatures, 25 and 30 °C, markedly enhanced phytotoxicity of picloram and muron.

The PDF includes a summary in Finnish.

• Kozlowski, E-mail: tk@mm.unknown
• Sasaki, E-mail: ss@mm.unknown
• Torrie, E-mail: jt@mm.unknown

The present investigation shows that injury to pines (Pinus silvestris L.) in the boreal coniferous zone (65 °N) occurs in winter conditions in the vicinity of a fertilizer processing plant, unless they are covered by snow. This kind of injury has multiple causes. Firstly, fertilizer dust discharged from the process operations may reduce the degree of xeromorphism of the needles, which further results in disorders of the water economy. Secondly, along with the wet fertilizer dust the needles absorb toxic substances, especially, fluorides and certain sulphur compounds. The amounts of fluorides, in particular, are large enough to bring about damage. The combined effect of these factors causes trees to die during winters with long periods of intense cold. It seems, therefore, that in the northern conditions pollution may have effects not observable in more southern regions.

The PDF includes a summary in Finnish.

• Havas, E-mail: ph@mm.unknown

• Aphalo, Faculty of Forestry, University of Joensuu, P.O. Box 111, FIN-80101 Joensuu, Finland; Current address Department of Biological and Environmental Science, University of Jyväskylä, P.O. Box 35, FIN-40351 Jyväskylä, Finland. E-mail: pedro.aphalo@jyu.fi
• Schoettle, Rocky Mountain Research Station, 240 West Prospect Road, Fort Collins, CO 80526, USA E-mail: aws@nn.us
• Lehto, Faculty of Forestry, University of Joensuu, P.O. Box 111, FIN-80101 Joensuu, Finland E-mail: tl@nn.fi