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PubMed1992

Clinical studies of employees in a sheet-forming process at a paper mill.

Formaldehyde resins are used to improve the wet strength of paper. During the sheet-forming process of paper manufacture, formaldehyde fumes are liberated. Twenty-two male subjects having such exposures in a paper mill and 27 unexposed subjects were clinically evaluated to determine the effect of low level formaldehyde exposure in a tropical country. The workers were exposed to 0.03 mg formaldehyde/m3 air as an 8-h TWA. Formic acid excretion in urine was 37.2 +/- 18.9 and 20.3 +/- 4.2 ug/L among the exposed and the unexposed subjects, respectively. Significantly more respiratory problems (31.8%) were observed among the exposed subjects as compared to controls. Complaints pertaining to gastrointestinal, musculoskeletal and cardiovascular systems were also more frequent in exposed subjects. In spite of formaldehyde concentrations being well within the prescribed ACGIH limits of 1 ppm, the high rates of sickness emphasise the need for detailed studies on formaldehyde-exposed subjects in tropical countries.

Adult↗

PubMed2004

Monitoring of a paper mill wastewater treatment plant using UV/VIS spectroscopy.

A submersible UV/VIS spectrometer was used to monitor a paper mill wastewater treatment plant. It utilises the UV/VIS range (200-750 nm) for simultaneous measurement of COD, filtered COD, TSS and nitrate with just a single instrument. The instrument measures in-situ, directly in the process. Paper mill wastewater shows typical and reproducible spectra at various process measuring points. There is a relative maximum at 280 mm due to the absorbance by dissolved organic substances, mainly ligninic acids. Comparison of absorbance spectra distinctly shows the decrease of this peak, indicating biological degradation throughout the treatment process. Summarising, one can say that paper mill wastewater cannot be monitored by a simple UV probe measuring only the absorbance at a single wavelength. The required information can only be gained from the whole spectra. Regarding plant control it is suggested that only the overall spectral information is used. Calibrations to conventional parameters are now merely carried out for purposes of reference-checking.

Calibration↗

PubMed2004

Water circuit closure with membrane technology in the pulp and paper industry.

In this study, membrane filtration as an internal purification method, "the kidney", in the pulp and paper industry is discussed. Membrane filtration is economically competitive and a very versatile process. It can be used to remove the enriched organic and/or inorganic loads either partially or totally from, for example, the mechanical pulping and paper making water circuits and it can be applied to various points within the process. With the so-called shear enhanced membrane modules very high fluxes, in ultrafiltration about 400 L/(m2h) and in nanofiltration fluxes almost 200 L/(m2h), have been obtained. Depending on the membrane, suspended solids (microfiltration), polysaccharides, extractives and high molar mass lignous substances (ultrafiltration) and multivalent salts (nanofiltration) can be removed. Ultrafiltration permeate can well be used in paper machine showers to replace fresh water. The quality of the nanofiltration permeate is significantly higher than that of ultrafiltration. The membrane processes can be enhanced by various pre-treatment techniques to produce higher permeate fluxes and to eliminate membrane fouling. Such pre-treatment methods are, e.g., chemical treatment, ozonation and biological treatment. The most cost-effective processes were chemical flocculation, pH adjustment and thermophilic aerobic biological treatment.

Filtration↗

PubMed2004

Ultrafiltration and nanofiltration in the pulp and paper industry using cross-rotational (CR) filters.

Ultra- and nanofiltration with high shear CR-filters have been utilized for cleaning of clear filtrates and effluents from the pulp and paper industry. The aim was to find out how different nanofiltration membranes operate at high shear conditions. The filtration efficiency of the membranes was evaluated by measuring flux, retention and fouling at various recovery and pH conditions. High fluxes (approximately 100 L/(m2h)) for nanofiltration membranes were measured when circulation waters from the paper machine were filtered at neutral conditions. In the filtration of discharge of external activated sludge treatment plants we measured fluxes around 150 L/(m2h) even at a concentration factor of 12. The best NF membranes removed over 80% of the organic carbon and of the conductivity and almost completely eliminated the color. With acidic waters fluxes and retentions were significantly lower. The NF270 membrane from Dow and the Desal-5 membranes from Osmonics had the highest flux and retention properties. However, the Desal-5 membrane lost its retention properties slowly, which restricts its use in the high shear CR-filter. CR-nanofiltration can be used in the pulp and paper industry without feed pre-treatment by ultrafiltration. This increases the attractiveness of high shear CR-nanofiltration.

Carbon↗

PubMed2004

Ovarian cancer and occupational exposure among pulp and paper employees in Norway.

OBJECTIVES: A cohort study of female pulp and paper workers in Norway has shown a significantly increased risk of ovarian cancer. Other than the involvement of hormonal and reproductive factors, little is known of the etiology of ovarian cancer. Asbestos and talc are two agents hypothesized to influence the development of the disease. The present study aimed to investigate the association between ovarian cancer and occupational exposure to asbestos, talc, and total dust among Norwegian pulp and paper workers. METHODS: Forty-six cases of ovarian cancer, with four controls each, were included in the study. Occupational exposure was assessed by combining work histories from personnel files, questionnaire information about production processes, and exposure assessments from the mills. To obtain information about possible confounders, cases and controls were invited to participate in a personal interview. RESULTS: The odds ratio for asbestos exposure was 2.02, 95% confidence interval 0.72-5.66. For talc exposure, the odds ratio was 1.10, and for ever exposure to total dust, it was below 1.00. The risk estimates did not essentially differ after adjustment for possible confounding variables. CONCLUSIONS: The results do not confirm an association between exposure to asbestos, talc, and total dust and ovarian cancer among Norwegian pulp and paper workers. However, the odds ratio for asbestos exposure was doubled, and control for established nonoccupational risk factors did not change the estimate. Therefore, the possibility that exposure to substances in the work environment contributes to the elevated risk cannot be rejected.

Asbestos↗

PubMed2006

[Rhinoconjunctivitis caused by paper tissues].

Rhinoconjunctivitis can be caused by allergenic as well as non-allergenic factors. When no allergy is involved, it is important to ask the patient about possible daily exposure to factors that may irritate the mucous membranes. The work environment may play a part, but other things may also be provoking factors, including paper tissues, which, besides the fibres of the paper itself, may contain chemical substances that irritate the mucous membranes. The treatment is to replace the paper tissues with well-washed cotton handkerchiefs. The use of a nasal steroid may be necessary for a short time.

Conjunctivitis, Allergic↗

PubMed2005

Physico-chemical characteristics of paper industry effluents--a case study.

This paper presents the characteristics of wastewater from a small paper mill which is using wastepaper as a raw material. After analysis it was found that the raw wastewater consisted of 202-294 mg/l and 2010-3200 mg/l of suspended and dissolved solids respectively while pH varied from 6.7-7.3. The BOD and COD values ranged from 210-310, 1680-2340 mg/l respectively. Due to the treatment of raw effluent, the SS and TDS of treated effluent were significantly decreased and the values ranged in between 118 mg L(-1) to 154 mg L(-1) and 645 mg L(-1) to 925 mg L(-1), respectively. The pH values of the treated effluent were higher than the raw effluent. The nitrogen, phosphorous and potassium content of treated effluent were found to be higher after the treatment of paper mill raw effluent. The low amount of nutrient content may be because of the use of chemicals in process section which do not contain such elements. The sodium, calcium and magnesium were found higher in treated effluent, which may be due to addition of chemicals during the pulping and production section.

Conservation of Natural Resources↗

PubMed1978

Factors influencing paper chromatographic analysis of technetium-99m phosphorus compounds: concise communication.

A single-paper chromatographic system has been developed, capable of resolving Tc-99m dioxide, [99mTc] pertechnetate and Tc-99m phosphorus compounds. The best separations are obtained with CM82 paper developed in 0.5 m naCl, and 3MM or ashless No. 40 paper developed in 1 M sodium acetate buffer. In these systems, 99TcO2 remains at the origin, while 99mTcO4--and Tc-99m phosphorus compounds move with Rf values of 0.56--0.75 and 0.80--1.0, respectively.

Chromatography, Paper↗

PubMed1990

Direct solid-phase time-resolved fluoroimmunoassay of 17 alpha-hydroxyprogesterone in serum and dried blood spots on filter paper.

We describe a direct, solid-phase time-resolved fluoroimmunoassay (TRFIA) for measuring 17 alpha-hydroxyprogesterone (17OHP) in serum and blood spots on filter paper. We used 17OHP-3-carboxymethyloxime (17OHP3CMO) coupled to polylysine as the label, which enabled incorporation of up to 34 atoms of europium per molecule of 17OHP, for a very high specific activity. The assay is based on competition between labeled 17OHP3CMO and 17OHP in blood specimens for polyclonal rabbit anti-17OHP antibodies. The antibody-label complex is separated by binding to anti-rabbit antibodies coated onto microtiter strips. The assay buffer contains danazol to displace 17OHP from steroid-binding proteins in serum. For serum samples, the assay is accomplished in 1 h of incubation at room temperature. The blood spot assay with filter paper discs involves incubation overnight at 4 degrees C. Results for both types of specimens from the same subjects correlated well. The lowest measurable concentrations of 17OHP (nmol/L) were 0.10 (3 SD) and 0.75 (3 SD) for serum and dried blood on filter paper, respectively. Intra- and interassay CVs were about 5-15% for both types of samples.

17-alpha-Hydroxyprogesterone↗

PubMed1990

Cancer epidemiology in the paper and pulp industry.

Several studies of pulp and paper workers have demonstrated increased risks for certain cancer sites, e.g. tumours of the lymphatic and haematopoietic system as well as stomach cancer. An impressive lung cancer excess was found among paper and board mill workers in Finland, but not in studies elsewhere. Individual exposures have not been estimated, neither has a job-exposure matrix been applied in any of the studies. Therefore, it is impossible to link any of the excesses to specific single compounds or mixtures, of which there are a multitude in the pulp and paper industries. Although there are high quantities of organic chlorine compounds in the process mixtures and waste, the compounds have low volatility and occupational exposures are not necessarily high. Estimations of individual occupational exposure should be mandatory in future epidemiological studies in this industry.

Humans↗

PubMed1985

Evaluation of the measurement of blood glucose levels on dried filter paper blood spots.

The measurement of blood glucose using discs punched from dried spots on filter paper has been examined as a method to monitor patients' home blood glucose results. We confirm that the method is precise, reproducible, and accurate, but show that impregnation of the filter paper with boric acid leads to an initial false elevation in measured glucose levels and does not improve stability of the sample more than does refrigeration. Degradation of blood glucose is insignificant over 28 days if samples are stored at -20 degrees C, and samples kept at 4 degrees C show minimal falls provided they are analysed within 7 days. The greatest breakdown of glucose was shown to occur during the first 48 hours after application. The filter paper glucose measurements correlated closely with parallel measurements using a Yellow Springs Glucose Analyser.

Blood Glucose↗

PubMed1988

[Immunoenzyme analysis using paper disks].

Filter paper discs have been used in the enzyme immunoassay (EIA) as solid phase instead of polystyrene plates. The use of paper discs has made it possible to achieve a multiple increase in the sensitivity of sandwich EIA, thus permitting the detection of Yersinia pestis capsular antigen at a concentration of 0.4 ng/ml. Paper discs can be used not only for the sorption of antigen and antibodies, but also for the affinity purification of preparations.

Adsorption↗

PubMed1988

Effect of lot-to-lot variability in filter paper on the quantification of thyroxin, thyrotropin, and phenylalanine in dried-blood specimens.

We prepared whole-blood pools to contain various concentrations of phenylalanine (Phe), thyroxin (T4), and thyrotropin (TSH) and applied them to six different lots of Schleicher & Schuell Grade 903 filter paper, two of which represented extremes for serum-absorbancy. Individual measured T4 values showed minimal overlap among all pools for each individual filter-paper lot and for all lots combined, but Phe values overlapped considerably among the high-concentration pools within and among lots. Individual TSH values also showed considerable overlap among the high-concentration pools for all lots combined, but little overlap within each lot. Maximum differences in mean observed values among lots ranged from 6% to 36% for all analytes. Assay results from hemolyzed blood specimens generally were lower than from intact-cell blood specimens for T4 and TSH, but slightly higher for Phe. Maximum among-lot differences in mean values ranged from 13% to 29% for all analytes when each tested lot was used for assay calibration. Lot-to-lot differences in measured values were not strongly related to serum absorbancy values. We conclude that routinely encountered within- and among-lot filter paper variability, as measured by serum-absorbancy, is not alone sufficient to cause gross quantification errors in neonatal screening programs.

Absorption↗

PubMed1988

The crisis facing printed medical literature. Acid paper.

Medicine strives to preserve the achievements of the past for the benefit of future clinicians and scientists. However, the paper on which medical journals are printed is steadily and irreversibly decaying. Since the late 1800s, most medical journals have been published on paper prepared with acids. In recent years, publishers, authors, and archivists have become aware of the destructive effects of acid decay on medical journals. Though the cause of deterioration is well understood, the choice of a remedy is still controversial. Remedies include acid-free paper, computerization, deacidification, and microfilm. These techniques are reviewed for their reliability, comprehensiveness, and cost-effectiveness. Microfilm is recommended above other techniques as the most immediately promising solution. The authors propose that publishers be required by law to submit archival quality microfilm as a condition for copyright protection.

Libraries, Medical↗

PubMed1986

The use of normal filter paper for "dot-immunobinding assay" of some antibodies.

Normal filter papers were used for specific detection of tiny amounts of antibodies against two penicillin amidase molecular forms from Escherichia coli, monoclonal antibodies of IgG and IgM class against lipopolysaccharide from Citrobacter O36 and IgM antibody against glycoprotein N from human red blood cells. For colour detection of antibodies bound to proper antigens adsorbed on the paper, second antibody-horse radish peroxidase conjugates and hydrogen peroxide with 4-chloronaphthol were applied. The use of filter paper for dot-immunobinding assay of antibodies gave similar results to those obtained with expensive nitrocellulose sheets used by other authors.

Antibodies↗

PubMed1987

Radioimmunoassay of somatomedin-C in filter paper discs containing dried blood.

We describe a simple radioimmunoassay (RIA) for estimating concentrations of somatomedin-C (Sm-C) in dried blood on filter paper. A single 3.2-mm blood spot specimen on filter paper is eluted overnight into buffer containing antibody and 125I-labeled Sm-C. The following day, bound and free hormones are separated by addition of goat anti-rabbit gamma globulin in 60 g/L polyethylene glycol solution. The correlation between values obtained for such blood-spot discs and the corresponding wet plasma is highly significant (r = 0.90, p less than 0.001). The relative concentrations (arbitrary units) of Sm-C as determined for specimens on filter paper from mothers and infants, and for cord bloods, are similar to those reported by others using acidified serum.

Adult↗

PubMed1985

Quality control of reflectometric determinations of glucose in dried blood spots on filter paper.

We evaluated the effect of sampling of capillary blood on filter paper on the later analysis for glucose. We found the method simple and reliable. Determination at the central laboratory of glucose in blood collected onto filter paper and comparison of the results with those obtained with test strips read in reflectometers at outpatient units is easy. Collecting duplicate samples on filter paper facilitates quality control by avoiding the complications that arise from using quality-control solutions that are not directly comparable with fresh blood, and it avoids the disturbances of test strip chemistry attributable to the glycolysis inhibitors added to blood samples intended for quality control.

Blood Glucose↗

PubMed1977

Modified paper chromatographic method for assay of myocardial depressant factor.

A simplified paper chromatographic technique for assaying myocardial depressant factor (MDF) is presented. In addition to a serine standard, deproteinized plasma samples from rabbits subjected to hemorrhagic shock were applied to paper and chromatographed. The spot in the chromatograms occurring at a migration distance of 1.6 to 1.8 times that of the standard (RS = 1.6-1.8) was found by bioassay to contain the MDF. The chromatographic spots were developed with ninhydrin and eluted with 3 ml of 1% NaHCO3. The absorbance at 570 nm (A570) of each eluate was measured and compared against the A570 value of the eluted serine standard. A direct linear relationship was shown between MDF chromatographic and bioassay values for each animal. This technique for paper chromatographic assay of MDF is as sensitive, specific, and reliable as bioassay, but offers clear advantages of small sample volume requirement, reduced analysis time, and ease of performance with routinely available laboratory equipment.

Animals↗