Determination of polycyclic aromatic hydrocarbons in urine from coke-oven workers with a radioimmunoassay

Heat and PAHs Emissions in Indoor Kitchen Air and Its Impact on Kidney Dysfunctions among Kitchen Workers in Lucknow, North India

Indoor air quality and heat exposure have become an important occupational health and safety concern in several workplaces including kitchens of hotels. This study investigated the heat, particulate matter (PM), total volatile organic compounds (TVOCs) and polycyclic aromatic hydrocarbons (PAHs) emissions in indoor air of commercial kitchen and its association with kidney dysfunctions among kitchen workers. A cross sectional study was conducted on 94 kitchen workers employed at commercial kitchen in Lucknow city, North India. A questionnaire-based survey was conducted to collect the personal and occupational history of the kitchen workers. The urine analysis for specific gravity and microalbuminuria was conducted among the study subjects. Indoor air temperature, humidity, wet/ dry bulb temperature and humidex heat stress was monitored during cooking activities at the kitchen. Particulate matter (PM) for 1 and 2.5 microns were monitored in kitchen during working hours using Hazdust. PAH_S in indoor air was analysed using UHPLC. Urinary hydroxy-PAHs in kitchen workers were measured using GC/MS-MS. Higher indoor air temperature, relative humidity, PM₁ and PM_2.5 (p<0.001) was observed in the kitchen due to cooking process. Indoor air PAHs identified are Napthalene, fluorine, acenaphthene, phenanthrene, pyrene, chrysene and indeno [1,2,3-cd) pyrene. Concentrations of all PAHs identified in kitchen were above the permissible OSHA norms for indoor air. Specific gravity of urine was significantly higher among the kitchen workers (p<0.001) as compared to the control group. Also, the prevalence of microalbuminuria was higher (p<0.001) among kitchen workers. Urinary PAH metabolites detected among kitchen workers were 1-NAP, 9-HF, 3-HF, 9-PHN and 1-OHP. Continuous heat exposure in kitchens due to cooking can alter kidney functions viz., high specific gravity of urine in kitchen workers. Exposure to PM, VOCs and PAHs in indoor air and presence of urinary PAHs metabolites may lead to inflammation, which can cause microalbuminuria in kitchen workers, as observed in the present study.

Polyurethane foam chips combined with liquid chromatography in the determination of unmetabolized polycyclic aromatic hydrocarbons excreted in human urine

A method suitable for the determination of unmetabolized polycyclic aromatic hydrocarbons (PAHs) excreted at trace levels (ng/L) in human urine for the monitoring of exposure of the general population to PAH contamination was developed. PAHs were determined, after enrichment by solid-phase extraction on polyurethane foam (PUF) chips, by HPLC with fluorescence detection. Different parameters affecting analyte extraction to the PUF, including urine salting-out and organic additives, and optimization of conditions for clean-up and desorption have been investigated. Optimized conditions were 40 mL acidified urine sample, added with magnesium sulfate, tetrahydrofuran and a 2 cm3 PUF chip, and extracted by shaking at 30 rpm for 1 h at ambient temperature. Desorption was performed, after a clean-up step with diluted sodium hydroxide, using a small amount of diethyl ether. The recovery of PAH congeners from spiked urines was >90% in the 2-100 ng/L range; the detection limit was 0.1-0.5 ng/L, depending on the considered PAH congener; day-to-day precision, at 50 ng/L native PAH content, was CV = 10-20%. The proposed technique provides a simple, economical and effective procedure for the determination of trace amounts of unmetabolized PAHs excreted in human urine spot samples.

Determination of polycyclic aromatic hydrocarbons in urine of coke oven workers by headspace solid phase microextraction and gas chromatography-mass spectrometry

Polycyclic aromatic hydrocarbons (PAHs) represent a complex mixture of toxic compounds that are ubiquitous in the environment. We investigated the utility of head space-solid phase microextraction (HS-SPME) to measure the following surrogate PAHs in urine: naphthalene (NAP), phenanthrene (PHE), pyrene (PYR), and benzo(a)pyrene (BAP), representing classes of 2-, 3-, 4- and 5-ring compounds, respectively. We then applied the method to urine from 28 coke oven workers (median levels (microg/l) were: NAP=3.65, PHE=1.51, PYR=0.003, BAP not detected) and 22 controls (median (microg/l) NAP=0.859, PHE=0.062, PYR=0.001, BAP not detected). Urinary levels of NAP, PHE, and PYR were all associated with exposure category (controls, side- and bottom-workers, and top-workers) but not with smoking status. Strong correlations were observed between urinary levels of NAP, PHE, and PYR in coke-oven workers. Our results indicate that unmetabolized 2-, 3- and 4-ring PAHs can be measured in urine by HS-SPME. Such measurements can be used to investigate the uptake and metabolism of complex PAH mixtures in humans.

Disposable amperometric immunosensor for the detection of polycyclic aromatic hydrocarbons (PAHs) using screen-printed electrodes

An amperometric immunosensor for polycyclic aromatic hydrocarbons (PAHs) was developed. The immunosensor was based on disposable screen-printed carbon electrodes. The coating antigen used was phenanthrene-9-carboxaldehyde coupled to bovine serum albumin (BSA) via adipic acid dihydrazide. Antibodies were monoclonal mouse anti-phenanthrene. The enzyme alkaline phosphatase (AP) was used in combination with the substrate p-aminophenyl phosphate (pAPP) for detection at +300 mV (vs. Ag/AgCl). Various assay types were compared. Good results were achieved with an indirect co-exposure competition assay with a LOD of 0.8 ng/ml (800 ppt) and an IC(50) of 7.1 ng/ml (7.1 ppb) for phenanthrene. An indirect competition assay could detect phenanthrene with a LOD of 2 ng/ml (IC(50): 15 ng/ml) and an indirect displacement assay with a LOD of 2 ng/ml (IC(50): 11 ng/ml) at a 5 microl surface coating of 8.8 microg/ml phenanthrene-BSA conjugate. A coating concentration of 2.2 microg/ml allowed detection with a LOD of 0.25 ng/ml (250 ppt) with the indirect competition assay. The influence of the coating concentration on the sensor performance was investigated. Cross-reactivities were tested for 16 important PAHs. Anthracene and chrysene showed strong cross-reactivity, whereas benzo[g,h,i]perylene and dibenzo[a,h]anthracene showed no cross-reactivity.

Biomonitoring of polycyclic aromatic hydrocarbons in human urine

Measurement of polycyclic aromatic hydrocarbons (PAH) metabolites in human urine is the method of choice to determine occupational and/or environmental exposure of an individual to PAH, in particular, when multiple routes of exposure have to be taken into account. Requirements for methods of biomonitoring PAH metabolites in urine are presented. Studies using 1-hydroxypyrene or phenanthrene metabolites including its phenols and dihydrodiols are summarized. The role of these PAH metabolites as established biomarkers and also more recent developments of PAH biomonitoring are discussed.

Monitoring polycyclic aromatic hydrocarbon metabolites in human urine: extraction and purification with a sol-gel glass immunosorbent

A new, rapid method for selective extraction of hydroxylated polycyclic aromatic hydrocarbons metabolites (OH-PAHs) in human urine was developed using an immunosorbent of anti-pyrene antibodies which were encapsulated in a sol-gel glass (SGG) matrix. Resulting chromatograms after immunoextraction of urine samples and HPLC analysis of the extracts were free from matrix interferences. The LODs for the determination of OH-PAHs in these difficult samples were in the low-ppt range (1-16 ng/L). In addition to its high selectivity, the immunosorbent proved to be robust and reusable. Obtained recoveries in spiked urine samples ranged from 83 to 107% for the hydroxyphenanthrene and hydroxypyrene compounds under investigation, while recovery for 3-hydroxybenzo[a]pyrene was only 45-62%. In a biomonitoring study, the SGG immunosorbent was successfully used for trace-level analysis of OH-PAHs in 20 human urine samples. Results were compared to data obtained by an independent reference analysis method and revealed good correlation between both methods.

32P-postlabelling of bulky human DNA adducts enriched by different methods including immunoaffinity chromatography

DNA adducts in lymphocytes and granulocytes of men exposed occupationally and environmentally to high concentrations of aromatic compounds in air were measured by the 32P-postlabelling method. Adducts in the same samples were characterized using nuclease P1 enrichment, butanol extraction and immunoaffinity purification with an antiserum raised against benzo[alpha]pyrene diol epoxide (BPDE). Only part of the adducts found in human samples were extracted by butanol. It also seemed, that only a small part of them belonged to the group of polycyclic aromatic hydrocarbons (PAHs) recognised by the antibody. Relative content of hydrophobic adducts and those with a structure similar to PAHs was higher in winter samples (when exposure to aromatic chemicals in air was higher) in comparison to samples collected in summer.

Evaluation of biomarkers in plasma, blood, and urine samples from coke oven workers: significance of exposure to polycyclic aromatic hydrocarbons

OBJECTIVE

The aim was to assess the significance of two biomarkers; antibody to benzo(a)pyrene DNA adducts and concentration of hydroxyethylvaline haemoglobin adducts in samples from a well studied group of coke oven workers. As a measure of exposure we have used 1-hydroxypyrene in urine.

METHODS

Urine and blood samples were collected from coke oven workers and a control group. Samples from coke oven plant workers were collected in January and June. 1-Hydroxypyrene was measured in urine by high performance liquid chromatography (HPLC), antibodies to benzo(a)pyrene DNA adducts were measured by ELISA and hydroxyethylvaline haemoglobin adducts were measured by gas chromatography-mass spectrometry (GC-MS).

RESULTS

Mean urinary 1-hydroxypyrene in samples from coke oven workers varied from 1.11 to 5.53 umol/mol creatinine and 0.14 umol/mol creatinine in the control group. Workers at the top side had the highest values of urinary 1-hydroxypyrene. Antibody to benzo(a)pyrene DNA adducts did not correlate with either 1-hydroxypyrene nor length of work at the coke oven plant. But antibody concentration in samples collected in January was predictive of the concentration in samples collected in June. A small non-significant increase in hydroxyethylvaline haemoglobin adducts was found in samples from coke oven workers relative to the control group when comparing smokers and nonsmokers separately.

CONCLUSION

1-Hydroxypyrene correlates well with exposure groups based on job description. Antibodies to benzo(a)-pyrene DNA adducts was related to people and not exposure. Work at a coke oven plant might lead to increased hydroxyethylvaline haemoglobin adducts.

Levels of pollutants and their metabolites: exposures to organic substances

The measurement of levels of organic pollutants and/or their metabolites in body tissues or fluids are specific markers of internal dose and, provided that the pharmacokinetic properties of the compounds in question are known, these levels may also be used as predictors of effects. Although historical data still remain to be very useful in environmental studies, more reliable exposure measures than combination of environmental levels and such estimators as residential history, job titles, life-style habits, individual perceptions, etc., are highly desirable. This has been clearly demonstrated in studies with 2,3,7,8-tetrachlorndibenzo-p-dioxin (TCDD), where more recent measurements of serum concentrations in persons earlier classified as belonging to exposed groups have indicated that severe misclassifications may have occurred in previously epidemiological studies. This also demonstrates that, in retrospective studies, levels of persistent organic compounds are useful as markers of exposure, as their tissue levels mainly reflect previous exposures. However, most organic compounds are readily metabolized and excreted from the human body, and in many instances it will not be possible with current methodology and instrumentation to detect transient organic pollutants at low levels in the blood. In most cases, the use of urine samples offers a better opportunity to provide samples containing detectable levels. Therefore, the measurement of non-persistent organic substances and/or their metabolites may find potential use in prospective environmental health studies, but the predictive value highly depends on proper timing and frequency of sampling according to their toxicokinetic behaviour. A few examples on the use of organic compounds and/or metabolites as biomarkers are given, e.g., polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs), polybrominated biphenyls (PBBs), ochratoxin A, polycyclic aromatic hydrocarbons (PAHs) and cooked food mutagens.