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Janeck J Scott-Fordsmand

Publications and source records attributed to Janeck J Scott-Fordsmand.

9 recordsLinked to original sources
PubMed2006

Uncertainty analysis of single-concentration exposure data for risk assessment--introducing the species effect distribution approach.

In recent years, the inclusion of uncertainty analysis in risk assessment has been much debated. One pertinent issue is the translation of the effects observed with a limited number of test species to a general protection level for most or all species present in the environment. In a number of cases, toxicity data may consist of data from tests employing only a control and one treatment. Given that more species (or processes) have been tested with the same treatment, the treatment can be considered as fixed, and the effect level of the individual species (or processes) can be considered as variable. The distribution of effects can be viewed as a species effect distribution for that treatment. The distribution will represent all organisms and may be used to predict the maximum impact on any fraction of all organisms (e.g., 95% of all species). Hence, it is possible to predict the maximum effect level, with a selected certainty, for a given fraction of all species.

Animals↗
PubMed2006

Effects of pesticides on soil invertebrates in laboratory studies: a review and analysis using species sensitivity distributions.

Species sensitivity distributions (SSD) and 5% hazardous concentrations (HC5) are distribution-based approaches for assessing environmental risks of pollutants. These methods have potential for application in pesticide risk assessments, but their applicability for assessing pesticide risks to soil invertebrate communities has not been evaluated. Using data obtained in a systematic review, the present study investigates the relevance of SSD and HC5 for predicting pesticide risks to soil invertebrates. Altogether, 1950 laboratory toxicity data were obtained, representing 250 pesticides and 67 invertebrate taxa. The majority (96%) of pesticides have toxicity data for fewer than five species. Based on a minimum of five species, the best available endpoint data (acute mortality median lethal concentration) enabled SSD and HC5 to be calculated for 11 pesticides (atrazine, carbendazim, chlorpyrifos, copper compounds, diazinon, dimethoate, gamma-hexachlorocyclohexane, lambda-cyhalothrin, parathion, pentachlorophenol, and propoxur). Arthropods and oligochaetes exhibit pronounced differences in their sensitivity to most of these pesticides. The standard test earthworm species, Eisenia fetida sensu lato, is the species that is least sensitive to insecticides based on acute mortality, whereas the standard Collembola test species, Folsomia candida, is among the most sensitive species for a broad range of toxic modes of action (biocide, fungicide, herbicide, and insecticide). These findings suggest that soil arthropods should be tested routinely in regulatory risk assessments. In addition, the data indicate that the uncertainty factor for earthworm acute mortality tests (i.e., 10) does not fully cover the range of earthworm species sensitivities and that acute mortality tests would not provide the most sensitive risk estimate for earthworms in the majority (95%) of cases.

Animals↗
PubMed2006

Effects of pesticides on soil invertebrates in model ecosystem and field studies: a review and comparison with laboratory toxicity data.

A systematic review was carried out to investigate the extent to which higher-tier (terrestrial model ecosystem [TME] and field) data regarding pesticide effects can be compared with laboratory toxicity data for soil invertebrates. Data in the public domain yielded 970 toxicity endpoint data sets, representing 71 pesticides and 42 soil invertebrate species or groups. For most pesticides, the most frequent effect class was for no observed effects, although relatively high numbers of pronounced and persistent effects occurred when Lumbricidae and Enchytraeidae were exposed to fungicides and when Lumbricidae, Collembola, and Arachnida were exposed to insecticides. No effects of fungicides on Arachnida, Formicidae, or Nematoda or of herbicides on Lumbricidae, Formicidae, or Nematoda were observed in any studies. For most pesticides, higher-tier no-observed-effect concentration or lowest-observed-effect concentration values cannot be determined because of a lack of information at low pesticide concentrations. Ten pesticides had sufficient laboratory data to enable the observed higher-tier effects to be compared with 5% hazardous concentrations (HC5) estimated from acute toxicity laboratory data (atrazine, carbendazim, chlorpyrifos, diazinon, dimethoate, gamma-hexachlorocy-clohexane, lambda-cyhalothrin, parathion, pentachlorophenol, and propoxur). In eight cases, higher-tier effects concentrations were within or below the 90% confidence interval of the HC5. Good agreement exists between the results of TME and field tests for carbendazim, but insufficient information is available for a comparison between TME and field studies for other pesticides. Availability and characteristics (e.g., taxonomic composition and heterogeneity) of the higher-tier effects data are discussed in terms of possible developments in risk assessment procedures.

Animals↗
PubMed2004

Do earthworms mobilize fixed zinc from ingested soil?

A wide range of organisms inhabit the soil and has to deal with soil-bound metals. The bioavailable fraction of metals may be estimated explicitly using the isotopic dilution technique. In the present paper, we evaluated the isotopic exchange technique for assessing the bioavailability of soil Zn (using 65Zn) to earthworms. To validate the technique, the worms were first exposed to various 65Zn levels, and errors due to soil entrained in the gut were evaluated. This exposure indicated no effect of gamma-radiation on growth (wet weight gain) of the organisms and that depuration of the earthworms minimized errors in labile pools determined by isotopic dilution. Our study further showed that the earthworms accessed 55-65% of the total Zn in the soil. The labile pool for the earthworms Eisenia andrei was similar to that for the plant Lactuca sativa, indicating that earthworms and plants to a large extent access the same fraction of soil Zn. Hence, the isotopic dilution technique has the potential to assess biologically available pool of Zn in soils. As lettuce is not known to significantly mobilize nonlabile metals in soil, this study indicates that Zn uptake by E. andrei is predominantly via the exchangeable pools (possibly the soil pore water) rather than dissolution of Zn held within soil particles or within soil organic matter or other food sources.

Animals↗
PubMed2004

Genetic variation in the enzyme esterase, bioaccumulation and life history traits in the earthworm Lumbricus rubellus from a metal contaminated area, Avonmouth, England.

Earthworms, Lumbricus rubellus, were collected in three successive years, 1997, 1998 and 1999 from 5, 6 and 4 sites, respectively, along a metal gradient near a smelter at Avonmouth, England. In total 271 worms were collected, 47 in 1997, 97 in 1998, and 127 in 1999. The worms were analysed for the enzyme esterase by means of agarose electrophoresis and for internal metal concentration. At one site collected in three successive years, 64 individuals of 66 were heterozygous for the esterase enzyme. The metal concentrations (Cu and Zn) in worms were significantly correlated with the total concentration and the CaCl2 extractable fraction of the metal in the soil. One of the homozygous esterase genotypes was significantly correlated with distance from the smelter, the extractable fraction of metals from soil, and the metal concentration in the worms. The other homozygous genotype was correlated with the CaCl2 extractable Cu and the Cu concentration in the worms. The internal levels of Cd, Cu, and Zn showed a higher classification potential (Discriminant Analysis) for 50 of 127 individuals, collected in 1999, when based on the original habitat of the earthworms than on the esterase genotype. The remaining 77 specimens, representing three sites, were exposed for 30 days in the laboratory to soils from four sites. For the individuals in this transplantation experiment, parameters measured were the esterase phenotype, internal metal concentration (Cd, Cu, and Zn), mortality, wet weight change, cocoon production, and cocoon hatching success. Cocoon production was highest among the worms from the most contaminated area, while worms from the least contaminated area had the highest hatching success. Neither the metal concentrations, in soil or internal, nor the life-history parameters could fully explain the genotypic distribution of esterase along the gradient. The internal concentrations of Cd, Cu and Zn in the worms used for the transplantation experiment showed the highest classification potential (Discriminant Analysis) when the prediction was based on the original habitat of the earthworms. The classification potential was less strong when based on esterase genotype and least on the transplantation conditions. Including life history traits did not enhance the prediction potential.

Animals↗
PubMed2004

Effects of pendimethalin at lower trophic levels--a review.

Pendimethalin's herbicidal action lies in its inhibition of the steps in plant cell division responsible for chromosome separation and cell wall formation. Terrestrial studies show that 10-20% of the herbicide evaporates during the first weeks after application. The remainder may dissipate biologically or chemically. Half-maximal dissipation time, or half-life (DT(50)) values vary from a few days to >200 days. Field and laboratory studies showed that reduced temperatures and drought prolong dissipation time to as long as 72-2094 days. In freshwater, pendimethalin concentrations reach 6 microg/L after runoff. In water the 10% lethal concentration (LC(10)) for Daphnia was 6 microg/L when exposed via suspended food. The LC(50) was 78 microg/L. An invertebrate field study showed that soil nematodes were reduced by 35-60% at pendimethalin application rates of 0.75 and 1.0 kg/ha, respectively. After application, soil microbiota is affected by pendimethalin for approximately 4 weeks. Plant-Rhizobium symbiosis is affected at application rates of 0.5-1.0 kg/ha.

Aniline Compounds↗
PubMed2004

The influence of application form on the toxicity of nonylphenol to Folsomia fimetaria (Collembola: Isotomidae).

The Collembola Folsomia fimetaria L. was exposed in the laboratory to a range of elevated soil and sewage sludge nonylphenol concentrations under three different contamination scenarios. When F. fimetaria were exposed to nonylphenol-spiked soil in a standard test design, a 10% effect concentration (EC10) of approximately 23 mg NP/kg was observed for reproduction. One of the primary sources of nonylphenol to agricultural soils is sewage sludge. Upon addition of nonylphenol to sewage sludge prior to homogeneously mixing this into the soil a 10% effect concentration (EC10) of approximately 6 mg NP/kg soil was observed for reproduction. Within soil core sewage, sludge is often not homogeneously distributed, but rather patchily distributed, enabling organisms to avoid it. To mimic the patchy distribution of sewage sludge, NP-contaminated sewage sludge pellets were distributed in noncontaminated soil and F. fimetaria were exposed to it. Exposed to the contaminated sewage sludge pellet F. fimetaria were affected by nonylphenol concentrations above approximately 19 mg NP/kg soil for reproduction. In this case the dose-response curve was considerably less steep than those of the two above exposure regimes.

Animals↗
PubMed2002

Field effects of simazine at lower trophic levels--a review.

Simazine is a triazine herbicide used in agriculture, pot-plant and tree production. The total concentrations (dissolved + adsorbed) in soil depend on the application rate, for example an application rate of 1500 g simazine/ha will result in approximately 4 mg simazine/kg in the top 1 cm. It may be spread to adjacent areas due to drift, runoff or evaporation. In fresh water concentrations approximately 4 microg simazine/l has been recorded. In aerial fallout--rain--concentrations of 0.680 microg simazine/l has been recorded. In both soil and water, degradation studies have in most cases shown DT50 times that vary between a few days and 150 days, indicating that total or near total disappearance time may be at least three times longer. Low temperatures and drought may prolong the dissipation time by a factor of two or more. Laboratory studies indicate that the primary site of decomposition in the aquatic environment is the sediment. Field studies showed deleterious effects of simazine on terrestrial invertebrates at application rates below 2 kg simazine/ha. The direct toxicity was not confirmed by laboratory results, however, these were sparse and did not cover a broad range of soil organisms. No field studies were found dealing with invertebrates, but laboratory studies have shown deleterious effects of simazine on aquatic invertebrates at concentrations above 20 microg simazine/l. Simazine is phytotoxic to many non-target species at rates below the recommended rate. At least under some environmental conditions, simazine can remain for a long time in the active layer and still be toxic to sensitive plants 1 year after application. Despite its phytotoxicity many plant species become more and more tolerant in cases of repeated use for many years and some have become resistant. Simazine is not highly toxic to soil microflora and algae, although some species definitely are affected both in an inhibitory and a stimulatory way. Most investigations predict no long-term consequences to soil and aquatic microflora in association with recommended and appropriate use giving rise to maximum expected environmental concentrations of 5 mg simazine/kg in soil and 4 microg simazine/l in water.

Animals↗