Effect of dust on the viability of Vibrio fischeri in the Microtox Test.

The standard Microtox test involving the bioluminescent bacterium Vibrio fischeri is a frequently used ecotoxicological bioassay whose EC50, values have been correlated to acute toxicity parameters of vertebrates, to irritancy measures, and to cytotoxicity indices. The aims were to explore the dependence of light output on viable cell number, with the latter estimated with the naked eye using a colorimetric tetrazolium salt method, the effects of dust on the bioluminescence and cell viability, how the viability of the cells is affected after spills, and how spills can be sampled. The lower limit of the linear dynamic range of the light-emitting bacterium was first defined to be 3.7 x 10(7) cells/ mL, compared with 37 x 10(7) cells/mL in the Microtox assay. The effects of dust were then explored in the working range by the method of standard additions by adding 5-, 10-, and 20-mg amounts of Standard Reference Material Urban Dust 1649a. This simulated dust samples collected by a cordless vacuum technique involving a filter cassette. A mass of 20 mg dust totally inhibited the Microtox test at all times (5, 15, and 30 min). Masses of 5 and 10 mg dust lowered the luminescence significantly by 20 and 64%, respectively, after 30 min. However, the viability test was totally inhibited by 5 mg of dust. A spectrophotometric modification of the viability test using a wavelength of 508 nm was developed that was twice as sensitive as the naked eye test, and was as sensitive as the Microtox test. Mechanical shock involved with spilling and sampling bacterial reagent on hard surfaces killed the luminescent bacteria as shown by inhibition of luminescence. The optimum filter cassette for Microtox reagent collection was a 25-mm 1.00-microm PTFE filter in a 25-mm Delrin holder operated at 4.0 L/min, with a Tygon sampling probe.

Optimized portable cordless vacuum method for sampling dry, hard surfaces for dusts.

Surface sampling in industrial/environmental hygiene is a growing field that needs validated standardized methods. There are few standard methods, one being the American Society for Testing and Materials (ASTM) method involving a portable, cordless air sampling pump. In the present work, the ASTM technique was modified to increase efficiency and versatility. A soil sample was first dried and sieved. Known weights of different sieved sizes (125 microns-180 microns, 90 microns-125 microns, and 63 microns-90 microns) were then sampled at an average flow rate of 4.0 +/- 0.2 L/min from a template of inner dimensions 10 cm by 10 cm on two different surfaces (rough and smooth). Five consecutive sampling passes were performed. For the smooth surface, the first pass efficiency for the largest particles were 45% +/- 45% (CV = 100%), and 75% +/- 20% (CV = 27%) for the smallest particles. After three passes, the efficiency independent of particle size exceeded 83 percent with a CV better than 11 percent. After five passes, the efficiency exceeded at least 85 percent with about the same precision as for three passes. The rough surface allowed higher efficiencies for the first two sampling passes. Three to five passes are recommended to achieve acceptable efficiencies for the surface loose dust/soil range 100 micrograms/cm2 to 1,500 micrograms/cm2.

Urinary biological monitoring markers of anticancer drug exposure in oncology nurses.

People handling anticancer drugs or their wastes may absorb these potent genotoxic agents. The aim of this study was to determine the utility of some general urinary markers among 24 female oncology nurses handling these drugs in comparison with 25 "unexposed" nurses. The markers were the Salmonella typhimurium reverse and forward mutation assays, total thioethers, and D-glucaric acid. The reverse mutation assay was the most specific and sensitive marker for anti-cancer drug exposure. Use of the marker battery was no great advantage as a screening tool relative to use of the reverse mutation assay alone. Better recording of work practices in nurse work logs would have improved interpretation of results.

Biological monitoring screening of patients provided antineoplastic drugs including adriamycin, cyclophosphamide, 5-fluorouracil, methotrexate, and vincristine.

The aim of the present study was to establish screening biomarkers of exposure to antineoplastic drugs administered to 11 patients undergoing cancer chemotherapy. Among the anticancer drugs administered were cyclophosphamide (all), Adriamycin (5 of 11), methotrexate (3 of 11), 5-fluorouracil (4 of 11), vincristine (3 of 11), megestrol acetate (1 of 11), and procarbazine (1 of 11). The noninvasive urinary parameters investigated were thioethers, D-glucaric acid, elements, and forward and reverse mutagenesis using bacterial bioassays. The data were analyzed in terms of the observed concentrations and those corrected for personal baseline. Personal baseline correction for parameters with significant nonexposure baseline levels was essential. While glucaric acid and thioethers were increased by the drug treatments, the correlations with baseline-uncorrected data showing an inverse relationship proved spurious, because saturation of the detoxification systems occurred at the high doses administered. Glucaric acid was also influenced by methotrexate and vincristine. Thioether content was affected by cyclophosphamide only. The forward mutagenesis assay was directly correlated to cyclophosphamide dose but the reverse assay was not, in the presence or absence of rat S9 fraction. The forward assay was not sensitive to the effects of smoking. Relative to controls, the elements changed by cyclophosphamide were K, S, and P. Those affected by Adriamycin were Ca, Mg, and Na; 5-fluorouracil affected Ca, Mg, Na, and C; methotrexate changed P and S. The forward mutagenesis assay and D-glucaric acid concentrations were the screening biomarkers best suited to monitoring for extent of exposure to these antineoplastic drugs.