Decolorization and detoxification of extraction-stage effluent from chlorine bleaching of kraft pulp by Rhizopus oryzae.
Rhizopus oryzae, a zygomycete, was found to decolorize, dechlorinate, and detoxify bleach plant effluent at lower cosubstrate concentrations than the basidiomycetes previously investigated. With glucose at 1 g/liter, this fungus removed 92 to 95% of the color, 50% of the chemical oxygen demand, 72% of the adsorbable organic halide, and 37% of the extractable organic halide in 24 h at temperatures of 25 to 45 degrees C and a pH of 3 to 5. Even without added cosubstrate the fungus removed up to 78% of the color. Monomeric chlorinated aromatic compounds were removed almost completely, and toxicity to zebra fish was eliminated. The fungal mycelium could be immobilized in polyurethane foam and used repeatedly to treat batches of effluent. The residue after treatment was not further improved by exposure to fresh R. oryzae mycelium. (+info)
Toxicity of combustion products from burning polymers: development and evaluation of methods.
Laboratory and room-scale experiments were conducted with natural and synthetic polymers: cotton, paper, wood, wool, acetate, acrylic, nylon, and urethane. Smoke and off-gases from single materials were generated in a dual-compartment 110-liter exposure chamber. Multicomponent, composite fuel loads were burned within a 100 m(3) facility subdivided into rooms. In chamber experiments, mortality depended on the amount of material burned, i.e., fuel consumption (FC). Conventional dose (FC)/mortality curves were obtained, and the amount of fuel required to produce 50% mortality (FC(50)) was calculated. With simple flame ignition, cotton was the only material that produced smoke concentrations lethal to rats; FC(50) values for cotton ranged from 2 g to 9 g, depending on the configuration of the cotton sample burned. When supplemental conductive heat was added to flame ignition, the following FC(50) values were obtained; nylon, 7 g; acrylic, 8 g; newsprint, 9 g; cotton, 10 g; and wood, 11 g. Mortality resulting from any given material depended upon the specific conditions employed for its thermal decomposition. Toxicity of off-gasses from pyrolysis of phosphorus-containing trimethylol propane-polyurethane foams was markedly decreased by addition of a flame ignition source. Further studies are needed to determine the possible relevance of single-material laboratory scale smoke toxicity experiments. Room-scale burns were conducted to assess the relative contributions of single materials to toxicity of smoke produced by a multicomponent self-perpetuating fire. Preliminary results suggest that this approach permits a realistic evaluation of the contribution of single materials to the toxicity of smoke from residential fires. (+info)
Diagnosis of rickettsial diseases using samples dried on blotting paper.
The use of filter paper is an inexpensive and convenient method for collecting, storing, and transporting blood samples for serological studies. In addition, samples occupy little space and can be readily transported without refrigeration. Rickettsial diseases often evolve according to an epidemic mode and are now considered reemerging diseases, especially in developing countries, under conditions where fieldwork could be difficult. The suitability of collecting whole-blood specimens on filter paper discs for rickettsial antibody assay was evaluated. Dried blood specimens from 64 individuals with antibodies to Coxiella burnetii, Bartonella quintana, or Rickettsia conorii were tested for rickettsial antibodies by microimmunofluorescence. Although occasional titers were 1 or 2 dilutions lower than those of tested serum samples, no statistically significant differences were observed. Among patients with negative serology, no false positives were found. This study demonstrated that the recovery of antibodies from finger-stick blood dried on filter paper after elution produces results comparable to those obtained by recovering antibodies from serum. Storing paper samples for 1 month at room temperature or at 4 degrees C did not significantly affect the level of antibodies recovered. This report shows the utility of this sample collection method in developing countries where refrigeration is not possible and venipuncture is problematic. (+info)
Airways inflammation among workers in a paper industry.
Exposure to organic dusts may cause airways inflammation in a large proportion of exposed persons. Most studies have relied on questionnaires and spirometry for diagnosis. To assess the possibility of determining the presence of inflammation using clinical diagnostic procedures, a study was undertaken among workers in a paper industry. Participants were 83 workers and 44 controls. Airborne endotoxin and (1-->3)-beta-D-glucan levels at the worksites were determined. The effects of this exposure were evaluated using a questionnaire, spirometry and measurements of airway responsiveness (methacholine) and levels of eosinophil cationic protein (ECP), myeloperoxidase (MPO), and C-reactive protein (CRP) in serum. The workers had a decreased baseline forced expiratory volume in one second (FEV1) and an increased airway responsiveness compared with controls. The concentrations of ECP and MPO were elevated compared with controls. There was a relation between exposure to endotoxin and (1-->3)-beta-D-glucan and airway responsiveness as well as ECP levels, when controlling for age, sex, smoking habits, atopy and asthma. The results suggest an increased prevalence of subjective respiratory symptoms, and an increased airway responsiveness among exposed workers. There was also a relationship between the serum concentration of eosinophil cationic protein and airway responsiveness. Taken together, the results suggest the presence of airways inflammation in the workers. (+info)
Screening of folate status with use of dried blood spots on filter paper.
BACKGROUND: Dried blood spots (DBS) on filter paper have been a successful and economical matrix for neonatal screening. OBJECTIVE: Our objective was to develop and evaluate an optimized method for DBS folate analysis and to assess DBS folate stability. DESIGN: DBS were eluted from paper by sonication in 5 g ascorbic acid/L containing 0.1% (by vol) Triton X-100 and hemoglobin folate values (HF; as pmol/g) were calculated from DBS eluate folate and hemoglobin concentrations. RESULTS: Over 95% of DBS folate was eluted during a standardized sonication cycle and DBS folate assay reproducibility was acceptable both within (CV: <8%) and between (CV: <9%) runs. HF means (+/-1 SD) from finger-stick DBS and conventional venous methods were 2513 +/- 1144 and 2607 +/- 1195 pmol/g, respectively, in blood samples taken concurrently from 80 donors, and they correlated well (r = 0.97, P < 0.001). HF values and erythrocyte folate measures may be interconverted by using the mean cell hemoglobin concentration. CONCLUSION: The DBS matrix has potential as an inexpensive and practical option for folate screening studies. (+info)
Dried plasma spot measurements of ferritin and transferrin receptor for assessing iron status.
BACKGROUND: Efforts to reduce the high global prevalence of nutritional anemia require the use of both reliable laboratory assays to distinguish iron deficiency from other causes of anemia and cost-effective methods for collection of blood specimens under field conditions. The suitability of using small plasma samples spotted and dried on filter paper for measurements of plasma ferritin and transferrin receptor was evaluated in the present study. METHODS: Blood specimens obtained from 73 male and 83 female subjects (19-40 years) representing a wide range of iron status were used to perform parallel measurements of plasma ferritin and transferrin receptor on whole plasma and spotted plasma samples. RESULTS: Ratio plots, evaluating the acceptability and precision of the spot method in ferritin and transferrin receptor assays, showed the expected proportion of data points within the 95% prediction interval. In the composite group of 156 subjects, both the whole plasma and plasma spot methods gave a geometric mean transferrin receptor/ferritin ratio of 18. The regression equation for the ratio was logy = 1.045 logx - 0.05126; r = 0.986; P <0.0001. The ratio of transferrin receptor/ferritin determined from plasma spots correctly identified all 12 subjects with iron deficiency anemia compared with 11 of the 12 for whole plasma measurements. CONCLUSIONS: Measurements of ferritin and transferrin receptor on plasma spotted and dried on filter paper are comparable to whole plasma values for the identification of iron deficiency anemia. The use of dried plasma spots will facilitate the collection, storage, and transport of samples in epidemiological studies of anemia prevalence. (+info)
Exhaled nitric oxide among pulpmill workers reporting gassing incidents involving ozone and chlorine dioxide.
The aim of the study was to investigate whether measurement of nitric oxide in exhaled air could be used for assessing the effects of irritants on the respiratory system, in this case recurrent ozone gassing in an occupational setting. The study population comprised bleachery workers (n=56) from a Swedish pulpmill carrying out ozone-based pulp bleaching since 1992 and controls (n=39). Both groups were investigated by measuring NO in exhaled air, methacholine challenge test and answers to a questionnaire concerning history of respiratory symptoms and accidental exposure to ozone peaks. There was no significant difference in NO output between exposed subjects and controls (median 67.2 versus 55.0 nL x min(-1), p=0.64). However, among bleachery workers reporting ozone gassings, the median NO output was 90.0 nL x min(-1) compared to 58.8 nL x min(-1) among those not reporting such incidents (p=0.019). There was no relation between exhaled NO and the prevalence of respiratory symptoms or bronchial hyperresponsiveness. In a multiple regression model, only reported ozone gassings were associated (p=0.016) with NO output. The results indicate an association between previous response to ozone gassing and nitric oxide output. The increased nitric oxide output among the bleachery workers reporting peak ozone exposure may indicate that chronic airway inflammation is present. Further studies are needed to evaluate the extent to which nitric oxide can be used for biological monitoring of respiratory health effects, and to relate it to other markers of airway inflammation. (+info)
Evaluation of filter paper blood lead methods: results of a pilot proficiency testing program.
BACKGROUND: Lead testing on dried filter paper (FP) blood spots is used routinely by some laboratories for lead poisoning screening. Proficiency testing (PT) as required under CLIA '88 laboratory regulations has not been available for these methods. METHODS: We describe a suitable PT scheme and evaluate FP laboratory performance based on program results. Monthly testing events consisting of five FP specimens were provided to six participating laboratories. Results were evaluated against target values determined by referee laboratories. RESULTS: Preliminary FP laboratory results showed poor agreement with specimen target values, exhibiting a mean absolute bias of 0.29 micromol/L (5.9 microg/dL). Five of six participating laboratories demonstrated significant improvement in later testing events, with bias decreasing to 0.12 micromol/L (2.5 microg/dL). Performance varied widely between the participating laboratories and appeared to be method dependent. When evaluated using CLIA blood lead acceptability criteria, the proportion of acceptable individual specimen results (n = 35) ranged from 54% to 100%. On a testing event basis (n = 7), the proportion of acceptable events ranged from 29% to 100%. CONCLUSIONS: A suitable FP PT program now exists to capably assist and monitor FP laboratories. Based on overt PT results, properly utilized FP testing methods can accurately measure blood lead concentration. (+info)