Effects of di(2-ethylhexyl) phthalate and dibutyl phthalate on the collembolan Folsomia fimetaria.

Lethal and sublethal effects of di(2-ethylhexyl) phthalate (DEHP) and dibutyl phthalate (DBP) on adult individuals of the collembolan Folsomia fimetaria were investigated in the laboratory by the use of small microcosms. Effects of DEHP and DBP were also tested on newly hatched collembolans in a multidish system. The endpoints were juvenile mortality, growth, and development. When exposed to DEHP, adults and juveniles were unaffected at all test concentrations, that is, up to 5,000 mg/kg. However, DBP caused increased adult mortality at 250 mg/kg and juvenile mortality at 25 mg/kg. For DBP, adult reproduction was a more sensitive endpoint than was survival, with an EC10 and EC50 of 14 and 68 mg/kg, respectively. Juvenile molting frequency seems to be a sensitive parameter, because number of cuticles produced by young springtails was reduced at 1 mg/kg. Toxicity was reduced when soil spiked with DBP was stored at 20 degrees C for a period of up to 28 d before adding the animals. Reduction in toxicity of DBP may be due a combination of degradation, evaporation, and adsorption of DBP to soil material. This was confirmed by chemical analyses, which showed a rapid initial disappearance followed by a much slower disappearance. Our results lead to the overall conclusion that significant adverse effects of phthalates on collembolans are not likely to occur as a result of normal sewage sludge application.

A follow-up study of male exposure to welding and time to pregnancy.

The aim of this study was to estimate whether male welding has an impact on couple fecundability (the probability of conceiving in a menstrual cycle). A sample of Danish couples without previous reproductive experience was recruited nationwide by postal letters to members of the union of metal workers and three other trade unions. Among 430 included couples, 201 males were metal workers and 130 were welders. The couples were followed for a maximum of six menstrual cycles from termination of birth control until a clinical pregnancy was detected. Compared with nonwelding metal workers the fecundability odds ratio (OR) of male exposure to welding was 0.86 (95% confidence interval [CI] 0.58-1.28). An interaction between male smoking and welding was found; within smokers the OR for welding was 0.40 (95% CI 0.17-0.95) and within nonsmokers it was 1.22 (95% CI 0.74-1.99). Previous welding exposure was negatively related to fecundability among smokers (OR 0.84 per year with mild steel welding, OR 0.76 per year with stainless steel welding). No significant results were found when comparing with an external group of nonmetal workers. Decreased fecundability among smoking welders attributable to both current and previous welding exposure is possible, but these findings were the results of subanalyses that were not part of the a priori hypothesis.

The Danish Environmental Specimen Bank--status of establishment.

In 1988 the Ministry of Environment, Denmark appointed a committee with the purpose of investigating the need for and the requirements of a Danish Environmental Specimen Bank. The purpose of the Danish Specimen Bank will be to collect and store samples from the Danish environment in order to make retrospective studies. The sampling strategy is to select various biotopes and from each biotope to sample at least one species of plant, one species of invertebrate and one species of vertebrate. Six basic types including all fourteen subdivisions of biotopes were selected. Seven species of plants, four species of invertebrates and eleven species of vertebrates were selected. The number of biotic samples in all will be 119 every second year. No abiotic sampling strategy has yet been selected. Samples will be stored in containers cooled with liquid nitrogen, to preserve them for at least 50-100 years. The capital investment and the annual operating cost for the Danish Specimen Bank are estimated to 2,500,000 DKr. (350,000 $US) and 550,000 DKr. (70,000 $US), respectively.