Toxicity and chemistry of aspen wood leachate to aquatic life: field study.

A dark, toxic leachate has been observed around woodpiles of trembling aspen (Populus tremuloides Michx.) cut in winter for pulp or structural lumber. We measured production of leachate from 18 m3 of harvestable aspen logs stacked in an open field near Dawson Creek, British Columbia, Canada.

Effects of pulp mill solids and three composts on early growth of tomatoes.

Compost has been proposed as a means of simultaneously diverting organic materials from landfills while producing a valuable product that improves tilth, organic matter content and nutrient supply of agricultural soils. Composts manufactured from different source materials may have markedly different properties however, even if they meet all regulatory requirements. We compared the capacity of composts made from three different combinations of organic wastes (horse manure and bedding, mink farm wastes, municipal solid waste (MSW) and sewage sludge) along with clarifier solids from a chemo-thermomechanical pulp mill, to enhance the growth of tomato (Lycopersicon esculentum L.

Design considerations to avoid bias in the construction of toxicity indices.

Species vary widely in their sensitivity to different toxicants. It is best to use a battery of toxicity tests, using organisms from very different trophic levels and taxonomic groups, to assess complex mixtures. The results of the various tests can then be collapsed into a toxicity index that will express the relative hazard of the different samples in a single number.