Uranium bioassay and radioactive dust measurements at some uranium processing sites in Egypt--health effects

The safety of radiation workers in the uranium mining industry requires close and continuous monitoring of their working conditions. In this study, external radiation surveillance, radioactive dust monitoring and the bioassay of uranium were carried out in some processing sites. As dust represents one of the most important sources of radiation exposure in mills and mines, dust monitoring and bioassays were performed for a sample of workers on the production lines. The concentration of uranium in air ranged from 22.6 x 10(-7) to 11.1 x 10(-5) Bq cm-3, and the exposure levels ranged from 1 to 80 microSv h-1. Laser fluorimetric determination of uranium in urine samples showed concentrations in the range 8.4-29.2 micrograms L-1. Renal function parameters, such as serum creatinine and urea, and hematological parameters were determined in an attempt to correlate them with radiation exposure and the health status of the workers. Urine specimens collected from workers at the ore crushing and separation site showed elevated concentrations of uranium (up to 29.2 micrograms L-1) and a strong correlation between these concentrations and the registered serum creatinine. The mean uranium excretion in the investigated group was more than 20 times the occupational exposure decision level for urine uranium of 0.8 microgram L-1.     

Protein adducts as biomarkers of exposure to aromatic diisocyanates in workers manufacturing polyurethane (PUR) foam

This work was undertaken to investigate the usefulness of diisocyanate-related protein adducts in blood samples as biomarkers of occupational exposure to toluene diisocyanate (TDI; 2,4- and 2,6-isomers) and 4,4'-methylenediphenyl diisocyanate (MDI). Quantification of adducts as toluene diamines (TDAs) and methylenedianiline (MDA) was performed on perfluoroacylated derivatives by gas chromatography-mass spectrometry (GC-MS/MS) in negative chemical ionisation mode. TDI-derived adducts were found in 77% of plasma and in 59% of globin samples from exposed workers manufacturing flexible polyurethane foam. The plasma levels ranged from 0.003 to 0.58 nmol mL(-1) and those in globin from 0.012 to 0.33 nmol g(-1). The 2,6-isomer amounted to about two-thirds of the sum concentration of TDA isomers. MDI-derived adducts were detected in 3.5% of plasma and in 7% of globin samples from exposed workers manufacturing rigid polyurethane foam. A good correlation was found between the sum of TDA isomers in urine and that in plasma. The relationship between globin adducts and urinary metabolites was ambiguous. Monitoring TDI-derived TDA in plasma thus appears to be an appropriate method for assessing occupational exposure. Contrary to TDI exposure, adducts in plasma or globin were not useful in assessing workers' exposure to MDI. An important outcome of the study was that no amine-related adducts were detected in globin samples from TDI- or MDI-exposed workers, alleviating concerns that TDI or MDI might pose a carcinogenic hazard. Further studies are nevertheless required to judge whether diisocyanates per se could be such a hazard.     

Comparison of different methods for extraction of polycyclic aromatic hydrocarbons (PAHs) from Sicilian (Italy) coastal area sediments

This paper describes a work aimed at improving the conditions of an extraction method, coupling GC-MS determination, for the analysis without cleanup phase, of polycyclic aromatic hydrocarbons (PAHs) from sediment samples. The automatic Soxhlet extraction in warm mode (using Extraction System B-811 Standard, Büchi) has demonstrated advantages for automation, reduced extraction time, and lower solvent use than for conventional Soxhlet extraction. Under these conditions, the recoveries are very good as they resulted greater than 85 % and, in most of the cases, near 100 %. The repeatability is also satisfactory (relative standard deviation less than 15 %). The detection limits are also acceptable and ranged from 0.001 to0.01 μg/kg dry weight. Fifty-four sediment samples were collected. The total concentration of the 17 compounds investigated, in samples of sediments collected from three Sicilian coastal areas, expressed as the sum of concentrations, varies from 99 to 11,557 μg/kg of dry matrix; concentrations of total PAHs in the sediments of Cala are two to three times higher than the other stations.     

顶空-气相色谱-质谱法测定水中痕量丁基黄原酸

建立了顶空-气相色谱-质谱联用测定水中丁基黄原酸的方法。丁基黄原酸在酸性条件下分解成易挥发的二硫化碳,可用顶空-气相色谱分离、质谱定量测定。与传统的分光光度法相比,该法简便、快捷,在0.010～1.00 mg/L范围内线性良好,准确度高,加标回收率为95.1%～100.6%,精密度好,相对标准偏差为3.1%～6.5%,方法检出限为0.002 mg/L,适用于水中丁基黄原酸的监测。     

A diffusive sampling device for the determination of formaldehyde in air using N-methyl-4-hydrazino-7-nitrobenzofurazan (MNBDH) as reagent

A new method utilizing the diffusive sampling of formaldehyde in air has been developed. Formaldehyde is sampled with the use of a glass fiber filter impregnated with N-methyl-4-hydrazino-7-nitrobenzofurazan (MNBDH) and phosphoric acid. The formaldehyde hydrazone formed is desorbed from the filter with acetonitrile and determined by high-performance liquid chromatography (HPLC) with UV/visible detection at 474 nm. The sampling rate was determined to be 24.7 mL min-1 with a relative standard deviation of 7% for 48 experiments. The measured sampling rates were not dependent on the formaldehyde concentration (0.1-1.0 mg m-3), sampling time (15-482 min) or relative humidity (20-85%). The detection limit was 70 micrograms m-3 for a 15 min sampling period and 2 micrograms m-3 for an 8 h sampling period.     

A rapid lateral flow immunoassay for the detection of fungal alpha-amylase at the workplace

Fungal alpha-amylase is a flour supplement which is added to improve the quality of bakery products. Various studies have shown that exposure to this enzyme is an important risk factor for the development of bakers' allergy and this allergy is reported to be one of the most frequent causes of occupational asthma. A rapid assay was developed to monitor exposure to occupational allergens directly at the workplace. The sensitivity of the developed assay is 0.32 ng amylase mL(-1) in a buffer system with the commercially available alpha-amylase preparation Fungamyl 1600S as the standard. Initial validation tests (n = 33) were performed with airborne and settled dust from an industrial bakery. The new lateral flow immunoassay detected amylase in 22 of the 26 samples regarded as positive in an enzyme immunoassay, and was negative for all seven enzyme immunoassay-negative samples, while the four lateral flow immunoassay-negative/enzyme immunoassay-positive samples all had levels below 2 ng mL(-1). The sensitivity of 2 ng mL(-1) of the amylase lateral flow immunoassay is sufficient for first screening purposes and, therefore, this simple and rapid assay may allow direct on-site demonstration of work-related hazards of bio-allergen exposure. This would be particularly useful in occupational hygiene practice, especially in traditional or small-scale bakeries which lack the technological skills for testing the exposure to respiratory allergens.     

Carbon disulfide at a Chinese viscose factory external and internal exposure assessment

This article presents the results of carbon disulfide exposure measurements in a Chinese viscose rayon factory. The objectives of the study were to identify the external exposure levels at a large factory and to investigate the 2-thiothiazolidine-4-carboxylic acid (TTCA) concentrations in the urine of the subjects who were exposed to carbon disulfide in the working place atmosphere. The metabolism of carbon disulfide in the exposed subjects was also studied in order to demonstrate the best points in time for the internal exposure sampling. The measurement of the amount of personal exposure to carbon disulfide in the air of the workplace was performed by GC-FPD; the presence of TTCA in the workers urine was analyzed by use of a modified HPLC method. The kinetics of TTCA excretion was studied by analyses at different time-points both during and after exposure to carbon disulfide in the subjects. A total of 155 personal samples were obtained. The carbon disulfide concentration in the staple viscose hall was 13.72 +/- 1.12 mg m-3 in terms of the geometric mean +/- geometric standard deviation, and was 20.05 +/- 1.33 mg m-3 in the filament spinning hall. The TTCA values in the subjects who worked in the staple spinning hall were 1.18 +/- 0.43 mg g-1 creatinine and 1.07 +/- 0.38 mg g-1 creatinine for subjects working in the filament spinning hall. The best time for TTCA sampling is at the end of the working shift, the TTCA excretion was stable for a period of 4-12 h after exposure of the subjects to the carbon disulfide. It might be that the Chinese have different anthropometric characteristics; a sampling bias may therefore appear among different races.     

Capillary microextraction for simultaneous analysis of multi-residual semivolatile organic compounds in water

Capillary microextractor (CME) in combination with a gas chromatograph-mass spectrometer (GC-MS) was employed for the determination of trace priority hazardous substances in water. Three groups of semivolatile organic compounds (SVOCs), i.e., chlorinated hydrocarbons, pesticides and polycyclic aromatic hydrocarbons (PAHs), were simultaneously determined. SVOCs were extracted from 7 mL of water samples on a 100 cm commercial gas chromatographic column (0.32 mm id x film thickness 0.25 microm, HP-5 capillary column) and eluted with only 3 microL of acetonitrile. The extractant was analyzed by GC-MS in the selected ion monitoring mode. The method showed good linearity over the concentration range 10 ng L(-1) to 3.0 mg L(-1) with correlation coefficients (r) greater than 0.99 and low limits of detection ranged from 10 ng L(-1) to 1.0 mg L(-1). High recovery (more than 80%) was obtained with relative standard deviation less than 10%. The method was successfully applied for trace level analyses of SVOCs in water samples.     

Environmental and biological monitoring of methyl ethyl ketone (MEK)

This study was conducted to evaluate the usefulness of various biological parameters for monitoring of workers exposed to methyl ethyl ketone (MEK). Fifty male workers from a large magnetic videotape factory participated in this study. Personal air samples were collected using 3M organic vapor monitors and analysed for MEK by gas chromatography with flame ionisation detector (FID). 10 mL of urine; blood (1 mL) and exhaled air were also collected at the end of an 8-hour workshift. The headspace GC method was applied for measurement of urinary and blood MEK. MEK in expired air was analysed directly by using a GC/FID.The correlation coefficients (r) between environmental MEK and all other biological parameters measured show significant positive relationships. The r for environmental MEK and urine MEK was 0.84; for blood 0.73 and for breath 0.64. The correlation coefficients between blood and urine was 0.72; blood and breath was 0.88 and urine and breath 0.60. These findings suggest that measurements of unmetabolised MEK in blood, exhaled air and urine can be used for biological monitoring of MEK exposure. Nevertheless, laboratory methodological assessment is in favour of measuring urinary MEK as it is non-invasive and does not have to be analysed immediately after collection.     

Lead (Pb) quantification in potable water samples: implications for regulatory compliance and assessment of human exposure

Assessing the health risk from lead (Pb) in potable water requires accurate quantification of the Pb concentration. Under worst-case scenarios of highly contaminated water samples, representative of public health concerns, up to 71–98 % of the total Pb was not quantified if water samples were not mixed thoroughly after standard preservation (i.e., addition of 0.15 % (v/v) HNO₃). Thorough mixing after standard preservation improved recovery in all samples, but 35–81 % of the total Pb was still un-quantified in some samples. Transfer of samples from one bottle to another also created high errors (40–100 % of the total Pb was un-quantified in transferred samples). Although the United States Environmental Protection Agency’s standard protocol avoids most of these errors, certain methods considered EPA-equivalent allow these errors for regulatory compliance sampling. Moreover, routine monitoring for assessment of human Pb exposure in the USA has no standardized protocols for water sample handling and pre-treatment. Overall, while there is no reason to believe that sample handling and pre-treatment dramatically skew regulatory compliance with the US Pb action level, slight variations from one approved protocol to another may cause Pb-in-water health risks to be significantly underestimated, especially for unusual situations of “worst case” individual exposure to highly contaminated water.     

Occupational exposure to rubber vulcanization products during repair of rubber conveyor belts in a brown coal mine

Several hundred chemical compounds were found in workroom environments in the rubber industry, but most of the published exposure data relate to the production of tyres; information from the "non-tyre" sections are very limited, if any. This study was carried out to identify chemical substances and measure their air concentrations in the repair shop of a brown coal mine in which damaged rubber conveyor belts were repaired. GC-MS and HPLC analysis of stationary air samples resulted in identification of aliphatic and aromatic hydrocarbons to C12, PAHs, alcohols, phenols, ketones, heterocyclic nitrogen and sulfur compounds. Quantitative evaluation of occupational exposure included determination of organic compound vapours collected on charcoal (GC-MSD), polycyclic aromatic hydrocarbons (HPLC), N-nitrosoamines and other amines (GC-NPD) and DNPH derivatives of aldehydes (HPLC) in the breathing zone of workers representing all job titles. The concentrations of investigated compounds were very low. Carcinogenic substances: N-nitrosoamines, benzene, PAHs were not present in workroom air in concentrations exceeding limits of detection of the analytical methods being applied; concentrations of methylisobutylketone, tetrachloroethylene, naphtha, aromatic hydrocarbons, phthalates and aldehydes were much lower than the respective occupational exposure limit values. The results indicate much lower exposure than that reported in the production of tyres and other fabricated rubber products.     

原子荧光法测定水中砷监测质量控制指标研究

通过全国多家实验室测定的大量监测数据研究了原子荧光法测定水中砷的质量控制指标,并与《水和废水监测分析方法》(第4版)中的相关指标进行了比较,旨在为环境监测工作提供质量控制依据和质量控制指标。研究表明,标准样品实验室内相对偏差的控制范围为小于等于4%;浓度小于0.05 mg/L的实际样品的相对偏差小于等于10%,浓度大于等于0.05 mg/L时相对偏差小于等于5%。实验室间相对偏差的控制范围为小于等于10%。相对误差一般控制在±15%以内,加标回收率为90%～110%。     

离子色谱法测定水中氯化物监测质量控制指标研究

研究了离子色谱法测定水中氯化物质量控制指标,提出精密度和准确度的建议控制指标,具有广泛指导意义。全国东、西、中部共12个省份的53家实验室参加测定工作。研究结果为：在一定的浓度范围内,RSD1．0％,RSD≤5．0％,RE≤±5．0％;加标回收率为95．0％～115．0％;RD≤4．0％。     

Analysis of polycyclic aromatic hydrocarbons in the atmospheric particulate: focused microwaves for a faster extraction method

In this paper, improvements obtained by using focused microwaves for extraction, in the analysis of polycyclic aromatic hydrocarbons (PAHs) adsorbed on particulate matter, are discussed. The method was tested on the following PAHs, which are considered to be among the most harmful with regard to carcinogenicity: benzo[a]anthracene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, indeno[1,2,3-cd]pyrene, dibenzo[a,h]anthracene. The extraction of PAHs and concentration of the sample can be performed in 3 h with a recovery of at least 70% and a maximum standard deviation of 4%. These steps are followed by clean-up on a SPE (solid-phase extraction) cartridge and analysis by GC-MS. Real samples collected in the urban area of Bari were analysed according to the proposed procedure.     

Correlation of urinary nickel excretion with observed 'total' and inhalable aerosol exposures of nickel refinery workers

An investigation of the relationship between observed nickel aerosol exposures and urinary nickel excretion was undertaken at a Scandinavian nickel refinery. The goal of the study was to assess the impact of nickel aerosol speciation, the use of particle size-selective sampling instrumentation and adjustment of urinary levels for creatinine excretion on the usefulness of urinary nickel excretion as a marker for exposure. Urinary nickel measurements and paired 'total' and inhalable aerosol exposure measurements were collected each day for one week from refinery workers in four process areas. The mean observed urinary nickel concentration was 12 micrograms L-1 (11 micrograms of Ni per g of creatinine). The strongest relationships between urinary excretion and aerosol exposure were found when urinary nickel levels were adjusted for creatinine excretion and when exposure to only soluble forms of nickel aerosol was considered. No significant difference was observed between measures of 'total' and inhalable aerosol in the ability to predict urinary excretion patterns. In the light of these results, it is recommended that consideration be given to the chemical species distribution of nickel aerosol in the use of urinary nickel measurements as a screening tool for cancer risk in occupationally-exposed populations.     

石墨炉原子吸收法测定水中铅的质量控制指标研究

通过对全国9个省份82家实验室监测数据的分析,研究确定了石墨炉原子吸收法测定水中铅的质量控制指标。建议控制值为：标准样品室内相对标准偏差（RSD）≤5.0%,实际样品相对偏差（RD）≤30.0%,标准样品室间相对标准偏差（RSD’）≤10%,标准样品相对误差（RE）≤±8.0%,加标回收率范围为90%～115%,同时还对方法的重复性和再现性指标进行了验证性研究。     

分光光度法测定水中六价铬的质量控制指标研究

通过国内多家实验室测定的大量数据,研究了分光光度法测定水中六价铬的质量控制指标,旨在为环境监测工作提供质量控制指标和依据.研究表明:样品质量浓度在0.04 ～0.5 mg/L范围内,标准样品室内相对标准偏差(RSD)≤4％,室间相对标准偏差(RSD′)≤15％,相对误差(RE)≤±10％(低浓度可适当放宽).实际样品质...     

Field measurement of lead in workplace air and paint chip samples by ultrasonic extraction and portable anodic stripping voltammetry

On-site measurement of lead in workplace air filter samples and paint chip samples by ultrasonic extraction and anodic stripping voltammetry (UE-ASV) was evaluated in the field during renovation and remodeling activities in residences having leaded paint. Aerosol and paint samples were collected using standard techniques, and the samples were analyzed on-site for lead content by portable UE-ASV. Lead in sample extracts was subsequently determined by atomic absorption (AA) spectrometry in a fixed-site laboratory. The remaining sample extracts plus undissolved material (air filters or paint particles) were then subjected to hot plate digestion in concentrated nitric acid-30% hydrogen peroxide prior to AA analysis for lead. Field UE-ASV lead data were thereby compared to UE-AA and hot plate digestion-AA results from fixed-site laboratory lead measurement. Determination of lead in air filter samples by UE-ASV (over the range of 5 microg to approximately 800 microg Pb per sample) was extremely well correlated with lead measurement by UE-AA and hot plate digestion-AA procedures. However, a significant negative bias associated with ASV measurement was observed, and this was attributed to a matrix effect. Lead measurement in paint chip samples by UE-ASV (over the range of approximately 10 to approximately 550 microg Pb g(-1)) was well correlated with lead measurement by UE-AA and hot plate digestion-AA procedures. However, correlation and precision were lower for lead measurement in paint samples as compared to aerosol samples, and a negative bias was also observed. Lead measurements by UE-AA were compared to lead determinations by hot plate digestion-AA; these data were highly correlated and demonstrated no significant bias. Thus it was concluded that the ultrasonic extraction procedure performed equivalently to hot plate digestion. It was reasoned that matrix effects due to the preparation and analysis of paint chip particles resulted in greater imprecision as well as negative bias by ASV measurement. Despite significant negative bias in this sample set, UE-ASV offers promise for on-site measurement of lead in samples of interest in occupational and environmental health.     

原子吸收法测定水中镉的质量控制指标研究

通过全国多家实验室的大量监测数据,研究分析了镉测定的质量控制指标,并与《水质镉的测定双硫腙分光光度法》（GB/T 7471-1987）和《环境水质监测质量保证手册》（第二版）进行了比较,旨在为环境监测工作提供质量控制依据和质量控制指标。研究表明,标准样品的精密度质量控制指标范围：RSD≤5.0%和RSD’≤8.0%;准...     

离子选择电极法测定水中氟化物质量控制指标研究

通过全国多家实验室的大量监测数据,研究分析了离子选择电极法测定水中氟化物的质量控制指标。研究表明,在0.5～4.5 mg/L范围内同一标准样品多次测定的质量控制指标为:室内相对标准偏差(RSD)≤4.0%,室间相对标准偏差(RSD’)≤8.0%,相对误差(RE)≤±10.0%。在0.06～7.0 mg/L范围内实际样品平行双样测定质量控制指标为:相对偏差(RD)≤5.0%。加标回收率范围为90%～110%。