ALBERT

Notizen: Summary Several formations within the lower part of the Dalradian Appin Group are characterised by calcareous and calc-silicate lithologies. Amphibole occurs in these metasedimentary units in a variety of habits, from fine-grained disseminated crystals, through radiating aggregates permeating the whole rock, to dark green layers consisting of over 90% amphibole. Electron microprobe analyses of these amphiboles exhibit simple compositional trends from tremolite, through tremolitic hornblende to magnesio-hornblende. The only significant substitutions are from tremolite towards alumino-tschermakite [MgSi ⇌ AlviAliv] and from tremolite towards ferri-tschermakite [MgSi ⇌ FeviAliv]. This is in marked contrast to amphiboles from nearby suites of metavolcanic rocks and intrusive metadolerites which exhibit four coupled substitutions, leading from tremolite towards the ferro-actinolite, edenite, alumino-tschermakite and ferritschermakite end-members. These distinctive compositional trends may aid the distinction between para- and ortho-amphibolites elsewhere. Tremolitic amphibole commonly constitutes a high proportion of the calc-silicate rocks, the only other phases present being quartz ± phlogopite. Carbonate minerals are notably absent. This suggests that the sedimentary protolith was high in Mg, such as a dolomitic marl, possibly containing some magnesite. Sedimentological considerations suggest deposition in tropical latitudes in restricted coastal lagoons forming part of an extensive stable shelf bordering a mature landscape.

Notizen: Abstract The acute toxicity of a technical formulation of pentachlorophenol (PCP) and pure pentachlorophenol to three age classes ofDaphnia magna, and adultD. pulex andD. galeata mendotae was determined by static toxicity tests. The influence of a number of factors on toxicity of PCP was also examined. The 48-hr LC50 estimates for adult daphnids of the three species exposed to pure PCP were 1.78, 4.59 and 0.51 mg/L, respectively, while those for the technical formulation were 2.57, 3.66 and 0.33 mg/L, respectively. There was little difference in toxicity between the technical and pure PCP; however, toxicity of both forms of PCP was influenced by duration of exposure, age (and/or size) and species of test organism and pH of the test solution. Pentachlorophenol caused a toxic response over a very narrow range of concentrations, with the greatest response occurring immediately between 0 and 24 hr. Pure PCP was equally toxic to all age classes ofD. magna but susceptibility to technical PCP decreased with maturation.D. g. mendotae was ten times more sensitive thanD. pulex to PCP. Pure PCP was significantly more toxic toD. magna at pH 5.5 than 7.0 with mean 48-hr LC50 values of 0.082 and 1.78 mg PCP/L, respectively. At 12°C, the toxicity of both forms of PCP toD. g. mendotae andD. pulex did not differ significantly from that at 20°C; however, technical PCP was significantly more toxic toD. magna at 12°C for an exposure duration of 48 hr. There was no effect of test container size (100, 250, 600 and 1,000 mL) on the toxicity of PCP toD. magna at 20°C with the lower pH of 5.5, suggesting that adsorption to glassware was not a factor in availability of PCP to test organisms. Beaker size had no effect on the toxicity of PCP toD. pulex at 20°C with test solutions having a pH of 7.0-8.0.

Notizen: Abstract Bioassays using rapid-cycling plants allow measurement of multiple endpoints and assessment of impacts on both growth and reproduction. Selections of Brassica rapa develop rapidly in a broad range of soils and are very consistent in production of flower and seed. Their sensitivity to variation in growth conditions was investigated to define the variables that most affect performance. Yield differences between soils were substantial, indicating the need for careful selection and use of control treatments. The sensitivity to contaminants was investigated with applications of mercury (Hg) and zinc (Zn) to three soils. In a sand soil, bloom initiation was slowed by 〈10 mg Hg kg−1 soil and 〈50 mg Zn kg−1 soil. In contrast, lettuce emergence and earthworm survival were less sensitive to these metals in this soil. Survival of Daphnia magna and the Microtox® assay in soil extracts were more sensitive to Hg than bloom initiation, but less sensitive to Zn. A similar relationship among the bioassays was observed for two finer-textured soils, although for these, effects were usually apparent only at soil metal concentrations 〉200 mg kg−1. Enzyme assays were included for comparison, but were not sensitive to Hg contamination. Rapid-cycling B. rapa selections are suitable for routine bioassays, and are representative of several widely distributed and utilized species.

Notizen: Abstract Improvements in the calibration techniques used in a Video Imaging Technique for Assessing Exposure (VITAE) were examined. A series of standard curves measuring change in fluorescence with increased tracer deposition within narrow pre-exposure skin tone groupings on volunteer human subjects were developed. Nine highly linear curves were generated. Data from these curves were used to develop calibration curves which permitted the computerized correction of fluorescence based on the pre-exposure skin fluorescence. VITAE estimates of dermal tracer deposition were highly correlated with application rates (r2=0.98). The fluorescent tracer 4-methyl-7-diethylaminocoumarin was found to be stable for up to 48 h in a greenhouse environment when applied to chrysanthemum foliage or alpha-cellulose patches. The percentage of tracer which could be dislodged from chrysanthemum foliage was constant over 48 h. Improvements in the VITAE calibration techniques increase its value in providing full-body dosimetric estimates of dermal exposure to pesticides in enclosed environments.

Notizen: Abstract Soil persistence and lateral movement of 2,4-D (2,4-dichlorophenoxy acetic acid) and picloram (4-amino-3,5,6-trichloropicolinic acid) were examined following their application as a stem-foliage spray for brush control on two power line rights-of-way. Ditches to collect runoff water were located 3, 10, 20, and 30 m downslope from the treated areas. Runoff water and soil samples were collected after 0.14, 0.43, 0.57, 1, 2, 4, 7, 8, 11, 15, 16, and 48 weeks and were analyzed for picloram and 2,4-D residues. Only 3 of 85 soil samples downslope from the target areas contained residues of 2,4-D, and only 1 of 85 down slope samples contained a detectable residue of picloram. Of 56 runoff water samples, only 11 contained 2,4-D residues and only 1 contained residues of picloram. The greatest distances downslope at which residues were detected in runoff water were 20 and 10 m for 2,4-D and picloram, respectively. No residues of either herbicide were recovered in soil or water at 15 weeks or 48 weeks after spraying. Despite normal rainfall frequency and amounts in the first several weeks after spraying in mid-June, significant runoff of either herbicide was not evident at either study site.

Notizen: Abstract Chronic toxicity test procedures (static, with renewal) were used to determine the chronic toxicity of sublethal concentrations of a technical formulation of pentachlorophenol (PCP) and pure pentachlorophenol toDaphnia magna. Test organisms 48+-12 h old were exposed for their entire lifespan (i.e., until death) to 0.01, 0.05, 0.1 and 0.5 mg technical PCP/L and 0.01, 0.087 and 0.1 mg pure PCP/L. Criteria used to assess chronic toxicity were mean time to appearance of the primiparous instar in the brood chamber, mean number of days to release of the first brood, mean number of broods produced per female, mean brood size per female, mean number of reproductive days, mean number of young produced per reproductive day per female and survivorship. Pentachlorophenol differentially affected maturation and reproduction but not survivorship or longevity. Mean number of broods produced per daphnid, length of the reproductive period, longevity and survivorship were insensitive criteria relative to mean time to appearance of the primiparous instar, time to release of first brood, brood size, and number of young produced per daphnid per reproductive day. Generally, there was little difference in toxicity of the three concentrations of pure PCP, for they significantly reduced mean brood size and rate of reproduction of young and significantly but differentially affected maturation. Technical PCP, at the highest concentration of 0.5 mg/L, significantly reduced mean brood size and the rate of production of young, and significantly delayed both time to appearance of the primiparous instar and release of the first brood. When differences in toxicity occurred, generally, pure PCP was more toxic than comparable concentrations of technical PCP. Although enhanced maturation was observed there was no compensatory reproduction. Similar conclusions regarding maturation and survivorship would have been derived from this study had it been terminated after the standard 21 d; however, the conclusions would have been different for reproduction. Only the highest concentration of technical PCP reduced brood size, the rate of production of young and total number of young produced per daphnid in 21 d. Only pure PCP at 0.05 mg/L caused daphnids to produce significantly fewer broods and, although the mean brood size was significantly larger than those in the controls, the mean number of young produced in 21 d was significantly reduced. These results differ substantially from those based on the entire life-cycle study and one of the most obvious differences is the much lower rates of young production in the entire life cycle study (2.41–3.03 young per daphnia per reproductive day) opposed to the first 21 days of the study (5.13–7.5 young per daphnia per reproductive day).

Notizen: Abstract Exposure of greenhouse chrysanthemum workers to the pesticide pirimicarb was measured by the Video Imaging Technique to Assess Exposure (VITAE) along with air monitoring and biological assessment techniques. Workers at five commercial chrysanthemum operations were video imaged prior to debudding plants which had been treated with a fluorescent tracer and the pesticide, pirimicarb, 36–48 h earlier. After 1–4 h of debudding, workers were again imaged and the rates of tracer deposition determined with the VITAE system. Tracer deposition from contact with treated foliage was found to increase in a linear fashion over 4 h. Greatest deposition occurred on the hands and arms and represented 42% and 20% of total exposure, respectively. No detectable air residue samples of pirimicarb were found while workers were debudding plants. Monitoring of four workers for pirimicarb and its urinary metabolites revealed no detectable residues following 4 h of contact with foliage, which had been treated 48 h earlier.

Notizen: Abstract Red-tailed hawks were exposed to sublethal levels of lead acetate for periods of 3 or 11 weeks. Alterations in the heme biosynthetic pathway were demonstrated after the first week of exposure to 0.82 mg lead per kilogram body weight per day. Activity of erythrocyte porphobilinogen synthase (aminolevulinic acid dehydratase) was depressed significantly and did not return to normal levels until 5 weeks after the termination of lead treatments. A rapid and relatively brief increase in erythrocyte free protoporphyrin and a slower but more prolonged increase in its zinc complex were also demonstrated with exposure to this dose of lead for 3 weeks. Less substantial decreases in hematocrit and hemoglobin levels occurred but only in the longer experiment with exposure to higher lead levels. Short term, low level lead exposure did not effect immune function significantly in the hawks, as measured by antibody titers to foreign red blood cells or by the mitogenic stimulation of T-lymphocytes. Increased lead exposure produced a significant decrease in the mitogenic response but had no effect on antibody titers.