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[Ethylene oxide sterilization. II. Influence of test devices on the performance of biological monitors and its evaluation].

In view of the importance of the assurance of the sterility of medical devices, with a large incidence of tubular forms, a study of biological monitors was undertaken, using paper as a carrier, the dimension of the test specimens being the variable considered. After the sterilization process in an industrial cycle, followed by the recovery of the surviving spores through inoculation of the carriers into thioglycolate broth, soybean-casein broth and this last with the addition of bromothymol blue. No differences were found between the growth promoting capacity of these 3 media. The effectiveness of sterilization was dependent on the dimension of the test specimens. The periodic determination of residual gas content on the test specimens, as well as the monitoring of the industrial environment demonstrate the need and importance of the legislation in force.

Bacillus subtilis↗

Biological monitoring of occupational exposure to inorganic arsenic.

OBJECTIVES: This study was undertaken to assess reliable biological indicators for monitoring the occupational exposure to inorganic arsenic (iAs), taking into account the possible confounding role of arsenicals present in food and of the element present in drinking water. METHODS: 51 Glass workers exposed to As trioxide were monitored by measuring dust in the breathing zone, with personal air samplers. Urine samples at the end of work shift were analysed for biological monitoring. A control group of 39 subjects not exposed to As, and eight volunteers who drank water containing about 45 micrograms/l iAs for a week were also considered. Plasma mass spectrometry (ICP-MS) was used for the analysis of total As in air and urine samples, whereas the urinary As species (trivalent, As3; pentavalent, As5; monomethyl arsonic acid, MMA; dimethyl arsinic acid, DMA; arsenobetaine, AsB) were measured by liquid chromatography coupled with plasma mass spectrometry (HPLC-MS) RESULTS: Environmental concentrations of As in air varied widely (mean 84 micrograms/m3, SD 61, median 40) and also the sum of urinary iAs MMA and DMA, varied among the groups of exposed subjects (mean 106 micrograms/l, SD 84, median 65). AsB was the most excreted species (34% of total As) followed by DMA (28%), MMA (26%), and As3 + As5 (12%). In the volunteers who drank As in the water the excretion of MMA and DMA increased (from a median of 0.5 to 5 micrograms/day for MMA and from 4 to 13 micrograms/day for DMA). The best correlations between As in air and its urinary species were found for total iAs and As3 + As5. CONCLUSIONS: To avoid the effect of As from sources other than occupation on urinary species of the element, in particular on DMA, it is proposed that urinary As3 + As5 may an indicator for monitoring the exposure to iAs. For concentrations of 10 micrograms/m3 the current environmental limit for iAs, the limit for urinary As3 + As5 was calculated to be around 5 micrograms/l, even if the wide variation of values needs critical evaluation and application of data. The choice of this indicator might be relevant also from a toxicological point of view. Trivalent arsenic is in fact the most active species and its measure in urine could be the best indicator of some critical effects of the element, such as cancer.

Adult↗

[Assessment of the health risk of a residential area contaminated with arsenic and lead. Biological monitoring in Mundelstrup].

Industrial use of toxic substances has resulted in contamination of the outer environment so that polluted area now constitutes a considerable environmental problem. This article describes biological monitoring employed as part of the basis for assessment of the health risk due to contaminated housing soil. As an example was chosen the environmental contamination with lead and arsenic in Mundelstrup Station Town, where a manure factory previously was situated. This area, which was found to be contaminated to a considerable extend with lead and arsenic, was subdivided for living area in 1921. The present material includes 99 residents from a housing area with 30 family houses with gardens in Mundelstrup. At the commencement of the investigation in 1988/1989, blood lead levels and arsenic levels in the urine were measured and the latter were repeated in 1989/1990. For both adults and children, the blood lead levels were the same as in the reference populations. Children below 12 years had in the average higher arsenic contents in the urine compared with women and men: 16.3 mu/l 8.6 mu/l and 11.5 mu/l, respectively. For both children and adults, the arsenic values were similar to those in a limited Danish reference population. In Ruston, an area in USA heavily polluted with arsenic, contamination of the surface was found to correspond to a factor ten times higher than in Mundelstrup where arsenic is measured at a deeper level. Correspondingly, arsenic values in the urine revealed higher average values in children, 30 micrograms/l for females and 65 micrograms/l for males. The average values for the reference group were found to be 11.3-13.0 micrograms/l.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Biological monitoring for mercury within a community with soil and fish contamination.

To assess the impact of elevated levels of inorganic mercury in soil and dust and organic mercury in fish, biological monitoring was conducted among Native Americans living next to an inactive mercury mine in Clear Lake, California. Of resident tribal members, 46% (n = 56) participated in biomonitoring. Urine mercury levels are equivalent to background, indicating that soil and dust exposures among study participants are not substantial. The average blood organic mercury level among study participants is 15.6 +/- 8.8 micrograms/l (n = 44), which is higher than levels reported by others among those who do not consume fish (2 micrograms/l). Consistent with results from other studies, a correlation between fish consumption and blood organic mercury is observed (p = 0.03). The margin between observed and established adverse effect levels for adults is examined for blood organic mercury and found to be less than 10-fold for 20% of the study population. Protective public health efforts for the study population and other similarly exposed populations, notably those who consume commercial fish products, are considered.

Adult↗

[Physiological and environmental factors affecting biological monitoring of exposure to organic solvent vapors].

A review of the literature was made on the physiological and environmental factors affecting pharmacokinetic behavior of organic solvent vapors in relation to biological monitoring of exposure to organic solvents. Among the physiological factors the importance is attached to body build (body weight and body fat content), sex, and physical activity. Environmental factors are centered on cigarette smoking, medications, coexistence of other solvents, dietary intake, and ethanol consumption with special emphasis of their effects on the hepatic metabolism of organic solvents.

Animals↗

Effects of consumption of ethanol on the biological monitoring of exposure to organic solvent vapours: a simulation study with trichloroethylene.

This study illustrates possible influences of consumption of ethanol on the pharmacokinetic behaviour of inhaled trichloroethylene (TRI) in relation to biological monitoring of exposure. The results were obtained for a standard male worker of 70 kg by physiologically based pharmacokinetic modelling. Depending on the pattern of consumption of ethanol, enzyme inhibition or induction was assumed to prevail in this worker. The inhibition and induction were modelled by assuming competitive metabolic interaction between TRI and ethanol and increased maximum velocity (Vmax) of TRI metabolism respectively. Ingestion of moderate amounts of ethanol before the start of work or at lunch time, but not at the end of work, caused pronounced increases in blood TRI concentrations and decreases in the urinary excretion rates of TRI metabolites, this effect lasting until the next day. The effects were smaller the higher the exposure concentration of TRI. Induction of TRI metabolism, supposedly by consumption of ethanol the previous evening, caused only small changes in the pharmacokinetic profile at 50 ppm, but appreciable changes at 500 ppm.

Alcohol Drinking↗

Quality assurance in the biological monitoring of lead exposure in China.

Based on the statistical data of the nationwide occupational diseases reporting in 1986-1988, lead poisoning stood the first place of chronic occupational poisonings in China. Biological monitoring of lead exposure is of paramount importance in both occupational and environmental health. In order to ensure lead testing data valid enough for taking actions of prevention and control, a quality assurance scheme including selection of reliable analytical techniques, establishing reference laboratory, application of standard reference materials, and conducting internal and external quality control program was implemented in China. Since the rigid assurance procedure was conducted during studies on "background levels of lead in non-exposure population" and "revision of the diagnostic criteria for lead", compatible and reliable results were obtained.

Aminolevulinic Acid↗

Biologic monitoring of exposure to organophosphorus pesticides in 195 Italian children.

One hundred ninety-five 6- to 7-year-old children who lived in the municipality of Siena (Tuscany, Italy), underwent biologic monitoring to evaluate urinary excretion of several alkylphosphates that are metabolites of organophosphorus pesticides. We evaluated dimethylphosphate (DMP), dimethylthiophosphate (DMTP), dimethyldithiophosphate (DMDTP), diethylphosphate (DEP), diethylthiophosphate (DETP), and diethyldithiophosphate (DEDTP). We obtained urine samples taken in the children's schools, and each sample was accompanied by a questionnaire about lifestyle and dietary habits. We found DMP and DMTP in detectable concentrations in the greatest number of samples (96 and 94%, respectively). The DMP values were geometric mean (GM) 116.7, [geometric standard deviation (GSD) 2.5], and a range of 7.4-1,471.5 nmol/g creatinine. The corresponding DMTP values were GM 104.3 (GSD 2.8) and a range of 4.0-1,526.0 nmol/g creatinine. DMDTP, DEP, DETP, and DEDTP concentrations were GM 14.1, (GSD 3.0), and a range of 3.3-754.6 nmol/g creatinine in 34% of the children; GM 33.2, (GSD 2.4), and a range of 5.1-360.1 nmol/g creatinine in 75% of the children; GM 16.0, (GSD 2.9), and a range of 3.1-284.7 in 48% of the children; and GM 7.7, (GSD 2.1), and a range of 2.3-140.1 in 12% of the children, respectively. The significant variable for urinary excretion of these metabolites in children was pest control operations performed inside or outside the house in the preceding month; however, the presence of a vegetable garden near the house rarely emerged. The urinary excretion of alkylphosphates in children was significantly higher than in a group of the adult population resident in the same province.

Agriculture↗

Experimental human exposure to N,N-dimethylbenzylamine: generation of a controlled atmosphere and biological monitoring.

The aim of the present study was to develop a method for generation of dimethylbenzylamine (DMBA) atmospheres in an exposure chamber and to investigate the possibility of using urinary DMBA metabolites for biological monitoring of exposure to DMBA. A DMBA atmosphere was generated by use of the gas-permeation principle. Six health male volunteers were exposed for 8 h to DMBA at air levels of 20, 45, and 80 microns/m3. Air levels of DMBA were analyzed by gas chromatography (GC). The total urinary amount of DMBA (U-SumDMBA; DMBA and metabolites that can be reduced to DMBA, e.g., DMBAO) was analyzed using GC-mass spectrometry (MS). The exposure chamber maintained very low (0-130 micrograms/m3) and steady concentrations for several weeks. DMBA uptake by inhalation was 76%. The amine was quickly distributed and biotransformed to nearly 100%. DMBA was eliminated in the urine with a half-time of 4.3 h. More than 50% was eliminated within 2 h of exposure. However, at all exposure levels the subjects continued to excrete DMBA the next morning. There was a significant correlation between the exposure to DMBA and the U-SumDMBA. Thus, U-SumDMBA may become an important biomarker for monitoring of industrial exposure to DMBA.

Adult↗

Biological monitoring of environmental exposure to mutagens among high school students in Jeddah.

Mutagenic and/or carcinogenic substances, which are present in the environment, are numerous. They include electrophilic compounds, polycyclic aromatic compounds such as benzo(a)pyrene which is a polyaromatic hydrocarbon. It is well known to be mutagenic and carcinogenic. Biological monitoring that depends on estimating a substance or one of its metabolites or one of its effective components in biological fluids such as urine and blood was carried out. Thioether concentration in urine indicates absorption of mutagenic and/or carcinogenic substances. Thiocyanates' concentration in urine was used as an indicator of absorption of mutagenic and/or carcinogenic haloacetonitriles. Urinary cotinine was used to estimate the extent of exposure to tobacco smoke, the heaviness of smoking, and whether the subject is smoker or not. Three hundreds and thirty two male students were randomly selected from eight secondary schools in Jeddah city. Their ages were more than 15 years and they were apparently free from illness. Every student filled a questionnaire. Random urine samples were obtained from all students. Thioether, thiocyanate, cotinine, and creatinine were measured in urine samples. There was a direct relation between urinary thioether and each of smoking index, food index, urinary thiocyanate, and cotinine. Urinary thioether shows an inverse relation with BMI. Urinary thiocyanate and cotinine showed direct relation with smoking index and with each of them and the other factor. This indicates interference between these indices and smoking is still one of the most misleading factors in researches that deal with the mutagenic and/or carcinogenic effects in the environment.

Adolescent↗

Biological monitoring of aluminium in renal patients.

During the past decade, aluminium (Al) has been shown to possess a potential for systemic toxicity. Renal patients form a high-risk group for Al poisoning, and biological monitoring is indicated to diagnose and prevent toxicity. Electrothermal atomic absorption spectrometry is the analytical method of choice for measuring Al levels. Special precautions have to be taken to prevent contamination with environmental Al or adsorption of Al to glassware during analysis. Since this metal is almost evenly distributed between plasma and erythrocytes, either plasma or whole blood may be used to estimate exposure to Al. Measurement in dialysis fluid is suitable to assess parenteral uptake. Hair analysis is of no value. The normal value in plasma is 7.3 +/- 2.0 micrograms/l (mean +/- SD, n = 10); toxic symptoms are mainly associated with levels above 100 micrograms/l. A dialysate level not exceeding 5 micrograms/l may be considered safe; intestinal absorption is then the only remaining, highly variable source of Al uptake.

Aluminum↗

Biological monitoring of workers exposed to benzene in the coke oven industry.

Workers in the coke oven industry are potentially exposed to low concentrations of benzene. There is a need to establish a well validated biological monitoring procedure for low level benzene exposure. The use of breath and blood benzene and urinary phenol has been explored in conjunction with personal monitoring data. At exposures of about 1 ppm benzene, urinary phenol is of no value as an indicator of uptake/exposure. Benzene in blood was measured by head space gas chromatography but the concentrations were only just above the detection limit. The determination of breath benzene collected before the next shift is non-specific in the case of smokers. The most useful monitor at low concentrations appears to be breath benzene measured at the end-of-shift.

Adult↗

Recommendations of the International Union of Pure and Applied Chemistry concerning analytical quality criteria in the biological monitoring of toxic metals.

A working party of the Commission of Toxicology of the International Union of Pure and Applied Chemistry has been set up to establish criteria to ensure analytical quality in the biological monitoring of toxic metals. Although the project has not yet been completed, some useful guidelines have been produced. They pertain to the description of the subject (so as to allow classification into a given "reference group"), the collection, storage and sampling of body fluids for trace-element determinations, and criteria to ensure the application of the correct analytical procedure, together with a quality-assurance protocol. It was agreed that a dedicated sampling protocol is required for each trace element in a particular matrix. Although it is impossible to specify this protocol together with all subsequent procedures in precise detail, the members of the working party have laid down general rules to be followed. This paper summarizes what has been achieved to date.

Environmental Monitoring↗

[20 years of biological monitoring (1976-1995) of occupational lead exposure in various Tuscan provinces].

We report the results of 24,475 blood lead determinations (PbB) performed by the Occupational Toxicology Laboratory of Florence between 1976 and 1995. Biological monitoring was carried out in 383 factories localized in the districts of Florence, Prato, Pistoia, Lucca and Pisa. The most represented production fields were colouring ceramic factories, artistic ceramics, transfer-pictures for ceramics, glass factories, typographies, glass decoration factories, chemical factories. In twenty years, the median values of PbB decreased from 48 to 17 micrograms/100 ml in males and from 40 to 8 micrograms/100 ml in females. The 95 degrees centile ranged from 84 to 46 micrograms/100 ml for males and from 63 to 42 micrograms/100 ml for females. In the 1988-95 period, we observed an increase of both the 95 degrees centile and the maximal values because of the inclusion of data from workers employed in factories where the "decorazione a scavo" technique, which is characterized by elevated environmental lead concentrations, was used. In the period 1991-93, the ranges of PbB observed in glass decoration factories were 13-160 micrograms/100 ml for males and 4-80 micrograms/100 ml for females, respectively.

Adolescent↗

Biological monitoring of 2,4-dichlorophenoxyacetic acid-exposed workers in agriculture and forestry.

This is a report on the application of a radioimmunoassay (RIA) for the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) in biological monitoring of occupationally exposed sprayers. Urinalysis was conducted on two workers involved in spraying 2,4-D sodium salt solution with car mounted ground rigs in agriculture and on the pilot and the mixer-loader of a helicopter crew applying 2,4-D dimethylamine salt for brush control in forestry. All sprayers showed detectable quantities of 2,4-D in morning urine samples voided over 4 or 6 days in the post-spraying period. The highest 2,4-D urinary concentrations of about 2.5 ppm could be measured in a car driver on the 3 day after exposure. The 2,4-D level in urine was much lower in forestry workers, with 0.365 ppm for the mixer-loader and 0.052 ppm for the pilot on the 1 day after spraying. Urinary 2,4-D concentrations in the agricultural study were adjusted for endogenous creatinine and, when normalized for body weight, resulted in a total 2,4-D uptake of about 5.7 or 84.9 micrograms/kg body wt. for a single spraying operation. Thus, the calculated absorbed dose was less than the NOAEL (no observed adverse effect level) of 10 mg/kg body weight per day by a large margin of safety. Further, the calculated amounts excreted seemed to be sufficiently reliable to be used for assessing the risk of human exposure to 2,4-D. However, more studies are desirable for confirmation of the association of urinary 2,4-D and creatinine excretion. Clearance occurs with a 12-h to 22-h half-life.

2,4-Dichlorophenoxyacetic Acid↗

Assessment of exposure to 2,4-dichlorophenoxyacetic acid in the chemical industry: results of a five year biological monitoring study.

Data on individual exposure to 2,4-dichlorophenoxyacetic acid (2,4-D) in herbicide production plants are limited. Hence, the urinary excretion of this herbicide was measured during a five year (1985-1989) biological monitoring study of 27 men and 18 women employees exposed during the production and formulation of 2,4-D and related sodium and dimethylamine salts. In separate studies, specimens of urine were collected in the morning, or during the last three hours of a working shift, or over a 24 hour period (1200 to 1200 or 0800 to 0800) and were analysed by an immunochemical method (2,4-D radioimmunoassay (RIA)). Urinary 2,4-D concentrations varied within a large scale from only a few micrograms/l to several 10s of mg/l. During a week, herbicide excretion increased, culminating on Friday. At the weekend, when no work was done, 2,4-D elimination decreased but did not return to zero in any case. After an interruption of exposure for about three weeks, urinary 2,4-D was no longer detectable. About five days after restarting work, body concentrations had built up again. Measurements of 2,4-D concentrations in air at different work-places showed that herbicide concentrations did not exceed 0.5 mg/m3. As well as inhalation, dermal 2,4-D absorption seemed to play an important part in total uptake of herbicide. Furthermore, a strong correlation was found (r = 0.9628) between 2,4-D urinary concentration, adjusted for endogenous creatinine, and the estimated amount of absorbed herbicide. Estimated absorbed doses were, in most cases, well below 0.1 mg 2,4-D/kg body wt/day. Sometimes this concentration was greatly exceeded. Thyroid hormone concentrations in blood were measured as well. No notable abnormalities were found. Exposed subjects were also typed for histocompatibility locus antigens (ABC antigens). The immunochemical determination of 2,4-D in specimens of urine proved to be a simple, cost effective, and non-invasive method to measure human exposure.

2,4-Dichlorophenoxyacetic Acid↗

Evaluation of the efficiency of respiratory protective equipment based on the biological monitoring of styrene in fibreglass reinforced plastics industries.

The purpose of the present study was to determine the efficiency of respiratory protective equipment in a fibreglass reinforced plastic factory by comparing results of environmental and biological monitoring of exposure to styrene. Five factories including 39 workers were investigated. Three types of respiratory protective equipment were tested: one was a half-mask air-purifying respirator equipped with a cartridge for organic solvents, another was a disposable gauze respirator impregnated with charcoal filter, and the third was a dust-proof respirator. The frequency of cartridge exchange of a half-mask respirator was twice a day only at one factory, and that was less than once a month at other factories. The site concentrations exceeded 20 ppm at 10 of the 82 sampling points (12.2%), and 22 of the 39 workers' (56.4%) personal exposure exceeded 20 ppm which is the current occupational exposure limit recommended by the Japan Society for Occupational Health. The efficiency of disposable gauze respirators and dust-proof respirators was low or rather zero. The average efficiency of half-mask respirators in which cartridges were exchanged twice a day and once a month was 83.6% and 46.6%, respectively. There was a significant disparity in the efficiency of the respirator depending on the frequency of cartridge exchange (p<0.05). Overall this study showed that even though a half-mask respirator is used and its cartridge is exchanged every half a day, workers exposed to a styrene concentration at or over 122 ppm are expected to inhale more than 20 ppm of styrene.

Adult↗

Biological monitoring of pyrethroid metabolites in urine of pest control operators.

Due to their low mammalian toxicity but high insectical activity, pyrethroids are increasingly used for pest control. The objective of the present study was the development of a biological monitoring program to determine exposure to pyrethroids. A diastereoselective detection of the major pyrethroid metabolites cis- and trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylic acid, cis-3-(2,2-dibromovinyl)-2,2-dimethylcyclopropanecarboxylic acid, 3-phenoxybenzoic acid and fluorophenoxybenzoic acid by capillary gas chromatography in combination with mass selective detection was applied. The limits of determination ranged between 0.5 and 1 microgram/l urine, depending on the metabolite concerned. It was demonstrated that pyrethroid metabolites were detectable in urine for a period of elimination up to 3.5 days after exposure to cyfluthrin. Fluorophenoxybenzoic acid was shown to be a suitable biomarker for exposure to cyfluthrin. The presented method was adequate for monitoring pyrethroids in occupationally exposed subjects.

Adult↗