Biological Exposure Index Research Articles

Design of a ruthenium(III) immobilized affinity material based on a β-cyclodextrin-functionalized poly(glycidyl methacrylate-ethylene dimethacrylate) monolith for the enrichment of hippuric acid.

Immobilized metal affinity chromatography has drawn great attention as a widespread separation and purification approach. In this work, ruthenium was firstly introduced into the preparation of immobilized metal affinity chromatography considering its affinity to N,O-donor ligands. A β-cyclodextrin-functionalized poly(glycidyl methacrylate-ethylene dimethacrylate) monolith was designed and employed as the supporting material in immobilized metal affinity chromatography. Thiosemicarbazide was introduced into the synthesis process, which not only acted as a bridge between β-cyclodextrin and glycidyl methacrylate, but also chelated with ruthenium because of its mixed hard-soft donor characteristics. The developed monolithic ruthenium(III)-immobilized metal affinity chromatography column was utilized for the adsorption and separation of hippuric acid, a biological indicator of toluene exposure. To achieve high extraction capacity, the parameters affecting the extraction efficiency were investigated with an orthogonal experiment design, L9 (34 ). Under the optimized conditions, the enrichment factor of hippuric acid was 16.7-fold. The method reproducibility was investigated in terms of intra- and interday precisions with relative standard deviations lower than 8.7 and 9.5%, respectively. In addition, ruthenium(III)-immobilized metal affinity chromatography material could be used for up to 80 extractions without an apparent change in extraction recovery.

Comprehensive Biological Monitoring to Assess Isocyanates and Solvents Exposure in the NSW Australia Motor Vehicle Repair Industry.

Urethane products that contain isocyanates are extensively used in the motor vehicle repair (MVR) industry and other industries such as furniture and cabinet-making as two-pack spray paints, clears, and adhesives. Attention has recently been refocussed on isocyanate-containing chemicals, particularly in paints. The spray painters in the MVR industry had a propensity to develop industrial asthma at a rate 80 times higher than the general public, which was previously reported in the UK. To track workers exposure to isocyanates, urine samples were collected from 196 spray painters who worked mainly in 78 MVR shops across 54 New South Wales (NSW) towns and suburbs. The biological monitoring also covered exposure testing to a wide variety of solvents including aromatic hydrocarbons, ketones, and alcohols. The main finding of the study was that 2.6% of the spray painters surveyed in the MVR industry in NSW that handled isocyanate-containing paints showed exposure to isocyanates; with 1.0% being moderately exposed, which is more than twice the current UK's Health and Safety Executive (HSE) Biological Monitoring Guidance Value (BMGV) of 1 µmol mol-1 creatinine. Potential exposures to toluene (a solvent often found in paint thinners) was monitored via hippuric acid (HA) urine levels and showed 2.6% of the spray painters surveyed to be over the US' American Conference of Government Industrial Hygienists (ACGIH) Biological Exposure Index (BEI) of 1010 mmol/mole creatinine for HA. The other solvents or their metabolites were all below their respective BEI; these comprised benzene, xylene, ethyl benzene, methyl ethyl ketone, acetone, methanol, and ethanol. These findings indicate that isocyanates and certain solvents exposure were occurring in the NSW Australia vehicle repair industry, albeit at lower levels than previous occupational biological monitoring studies that showed higher exposure levels, particularly for isocyanates. One reason for this could be the increasing use of water-based paints in the industry, resulting in lower than expected isocyanate and solvent metabolite levels detected in this more recent study. Further, the completion of sample context form, along with spot urine collection in relation to the isocyanate exposure monitoring work details will provide crucial information to interpret the biological analysis results. The development of new biomarkers of isocyanate oligomer-derived triamines should be incorporated in the assessment of isocyanate exposure in the MVR industry to provide a more complete picture of isocyanate exposure.

Determination of urinary trans,trans-muconic acid using molecularly imprinted polymer in microextraction by packed sorbent followed by liquid chromatography with ultraviolet detection.

trans,trans-Muconic acid (tt-MA) has been introduced as biological exposure index for workers exposed to benzene. In the present study, for the first time, a novel and easy-to-use analytical method based on molecularly imprinted polymer (MIP) in microextraction by packed sorbent (MEPS), followed by high-performance liquid chromatography with ultra-violet detection (MIMEPS-HPLC-UV) was developed to determine tt-MA in urine samples. Fourier transform infrared spectroscopy was used for MIP characterization. The imprinting effect on the MIP was also evaluated. Furthermore, various parameters that affect the MEPS performance were investigated, including extraction cycles, sample volume, as well as the type and volume of washing and elution solvents. The optimised procedure was selective, sensitive, rapid and both user- and environmentally-friendly. A seven-point calibration curve was obtained in the range of 0.015-2μg/mL (R2=0.9986). The extraction recovery was >89.8%. The limit of detection and limit of quantitation for tt-MA were 0.015 and 0.05μg/mL, respectively. The within- and between-day precisions, given as percent relative standard deviation, were in the range of 3.4-4.7% and 3.5-6.6%, respectively. Accuracy was -8.4 to -10.2% in urine samples. The developed method is suggested as an alternative to existing conventional SPE methods for biomonitoring of benzene-exposed subjects.

Urinary cadmium levels in active and retired coal miners

ABSTRACTA meta-analysis, based upon 24 publications, showed a significantly elevated risk for urinary bladder cancer amongst miners. In European underground hard coal mining areas, an increased risk for urinary bladder cancer development was noted among hard coal miners, in particular in three investigations in the greater Dortmund area. However, the cause remains unclear. As cadmium (Cd), which was reported to be a bladder carcinogen in humans and is a constituent of coal, the aim of this study was to determine urinary Cd levels in active and retired hard coal miners and assess whether hard coal miners demonstrated elevated metal levels. In total, 103 retired and 25 active hard coal miners as well as 18 controls without any history of hard coal mining were investigated for urinary Cd levels. Urinary Cd concentrations, in addition to other elements, were analyzed in spot urines by ICP-MS-based multi-element analysis in a Department for Forensic and Clinical Toxicology. Limit of detection (LOD) for Cd was 0.5 μg/L. Reference value for occupationally non-exposed working age population was 0.8 μg/L. In total, 49% of all underground coal miners were exposed to coal dust, 12% to grinded rock, and 39% to both. Urinary Cd levels in retired as well as active coal miners and controls were clearly below the Biological Exposure Index. Urinary Cd concentration is a suitable biomarker to evaluate the metallic load of the body, as the half-life is > than 10 years. The detected urinary Cd levels in retired and active coal miners indicated underground hard coal miners were not apparently exposed to Cd to a occupationally-relevant concentration.

The potential DNA toxic changes among workers exposed to antimony trioxide.

Occupational exposure to antimony has gained much interest when specific toxic effects were noticed among workers processing antimony. Thus, the aim of the present work was to investigate the potential DNA oxidative damage occurring among Egyptian workers occupationally exposed to antimony trioxide. The study was conducted on 25 subjects exposed to antimony trioxide while working in the polymerization process of polyester in Misrayon and Polyester Fiber Company, KafrEldawwar, Beheira, Egypt. Urinary antimony levels were assessed using inductive coupled plasma-optical emission spectrometry (ICP-OES) and considered as a biological exposure index. DNA damage and total oxidant capacity (TOC) were assessed using ELISA. DNA damage was detected in the form of increased apurinic/apyrimidinic (AP) sites among antimony trioxide-exposed workers compared to control subjects, but it could not be explained by oxidative mechanisms due to lack of significant correlation between DNA damage and measured TOC. Antimony trioxide might have a genotoxic impact on occupationally exposed workers which could not be attributed to oxidative stress in the studied cases.

Nitroethane Documentation of proposed values of occupational exposure limits (OELs)

Nitroethane is a colorless oily liquid with a mild fruity odor. It is used mainly as a pro-pellant (e.g., fuel for rockets), and as a solvent or dissolvent agent for cellulose esters, resins (vinyl and alkyd) and waxes, and also in chemical synthesis.Occupational exposure to nitroethane may occur during the process of its production and processing. There are no data on air concentra-tions of nitroethane in occupational exposure. In 2010–2015, workers in Poland were not exposed to nitroethane concentrations exceed-ing the maximum allowable value – 75 mg/m3 (the limit value valid since 2010).Nitroethane can be absorbed into the body via inhalation of its vapors or by ingestion.The discussed cases of nitroethane acute poi-soning caused by an accidental ingestion of artificial fingernail remover containing pure nitroethane concerned children under three years. Few hours after ingestion, cyanosis and sporadic vomiting were observed in children. The methemoglobin level reached 40÷50%.Neither data on chronic nitroethane poisoning in humans nor data obtained from epidemio-logical studies are available.On the basis of the results of acute toxicity studies nitroethane has been categorized in the group of hazardous compounds. However, eye and dermal irritation or allergic effects have not been evidenced. The studies of sub-chronic (4 and 90 days) and chronic (2 years) exposure to nitroethane per-formed on rats and mice (concentration range 310 ÷ 12 400 mg/m3) revealed the methemo-globinogenic effect of this compound and a minor damage to liver, spleen, salivary gland and nasal turbinates.Niroethane has shown neither mutagenic nor carcinogenic effects. Its influence on fertility has not been evidenced either. After chronic exposure (2 years) of rats to ni-troethane at concentration of 525 mg/m3 (the lowest observed adverse effect level – LOAEL), a slight change in a body mass of exposed fe-male animals and subtle changes in biochemi-cal parameters were observed, but there were no anomalies in hematological and histopatho-logical examinations.The value of 62 mg/m3 has been suggested to be adopted as the MAC value for nitroethane after applying the LOAEL value of 525 mg/m3 and relevant coefficients of uncertainty. The STEL value for nitroethane was proposed ac-cording to the methodology for determining short term exposure level value for irritating substances as three times MAC value (186 mg/m3) to prevent the effects of sensory irri-tations in humans. Because of its methemoglo-binogenic effect, 2% Met-Hb has been suggest-ed to be adopted as the value of biological ex-posure index (BEI), like the value already adopted for all methemoglobinogenic sub-stances.The Scientific Committee on Occupational Exposure Limits (SCOEL) proposed the time-weighted average (TWA) for nitroethane (8 h) as 62 mg/m3 (20 ppm), short-term exposure limit (STEL, 15 min) as 312 mg/m3 (100 ppm) and “skin” notation.Proposed OEL and STEL values for nitroethane were subjected to public consultation, con-ducted in 2011 by contact points, during which Poland did not raise any objections to the pro-posals. The proposed values for nitroethane by SCOEL has been adopted by the Advisory Committee on Safety and Health at Work UE (ACSH) and included in the draft directive establishing the IV list of indicative occupa-tional exposure limit values.

Water compatible molecularly imprinted nanoparticles as a restricted access material for extraction of hippuric acid, a biological indicator of toluene exposure, from human urine

The authors describe the preparation of molecularly imprinted nanoparticles (MINPs) for the solid phase extraction of hippuric acid (HA). The MINPs consists of a water-compatible organic-inorganic silica composite which was obtained from a functionalized silica by the sol-gel method. HA acted as the template, 3-aminopropyl trimethoxysilane as the functional monomer, and tetraethoxysilane as the crosslinker. Subsequently, methacryloxypropyltrimethoxysilane was used as a coupling agent to deposit a hydrophilic acrylamide coating onto the surface of the MINPs. The morphology and structure of the resulting restricted access material (referred to as RAM-MINP) were characterized by scanning electron microscopy, transmission electron microscopy and Fourier transform infrared spectroscopy. Solid phase extraction of HA was accomplished by passing urine samples through a RAM-MINP-packed SPE cartridge. Following elution, HA was quantified by HPLC using UV detection at 228 nm. The effects of sample pH, amount of sorbent and eluent and washing solvent volumes were optimized by experimental design methodology under response surface methodology. Under optimized conditions, the mean extraction efficiency of HA from spiked samples is adequately repeatable, with relative standard deviations of <6.1%. The limits of detection and quantitation are 0.15 and 0.25 μg.L−1, respectively.

In utero exposure to fluoride and cognitive development delay in infants

The objective of this study was to evaluate the association between in utero exposure to fluoride (F) and Mental and Psychomotor Development (MDI and PDI) evaluated through the Bayley Scale of Infant Development II (BSDI-II) in infants. The sample included 65 mother-infant pairs. Environmental exposure to F was quantified in tap and bottled water samples and F in maternal urine was the biological exposure indicator; samples were collected during the 1st, 2nd and 3rd trimester of pregnancy. The mean values of F in tap water for the 1st, 2nd and 3rd trimester were 2.6±1.1mg/l, 3.1±1.1mg/l and 3.7±1.0mg/l respectively; above to 80% of the samples exceeded the reference value of 1.5mg/l (NOM-127-SSA1-1994). Regarding F in maternal urine, mean values were 1.9±1.0mg/l, 2.0±1.1mg/l and 2.7±1.1mg/l for the 1st, 2nd and 3rd trimester respectively. The infants with MDI and PDI scores less than 85 points were 38.5% and 20.9% respectively. After adjusting for potential confounding factors (gestational age, age of child, marginalization index and type of water for consumption), the MDI showed an inverse association with F levels in maternal urine for the first (β=−19.05, p=0.04) and second trimester (β=−19.34, p=0.01). Our data suggests that cognitive alterations in children born from exposed mothers to F could start in early prenatal stages of life.

Oxidative Stress Index (OSI) in Children Chronically Exposed to Volatile Organic Compounds (VOC) and their Relation with Genetic Polimorphysms

INTRODUCTION The Atoyac River located in the Tlaxcala and Puebla states in Mexico, is receiving domestic and industrial discharges, causing a dramatic deterioration of the environment; various diseases have been reported like leukemia and renal failure on the Atoyac zone habitants that could be related to industrial water pollution. The objective of the research is to study the OSI in children chronically exposed to VOC carried by the river (toluene, xylene, ethyl-benzene and styrene). METHODS 91 children were studied in the area near the river Atoyac and 61 children in a control site (age range: 8-13, no diagnosed chronic diseases). OSI was measured in plasma samples using the total antioxidant capacity (TAC) and the total oxidant status (TOS) based on Erel’s method. Health parameters and anthropometric data were also determined. VOC metabolites were measured in urine. Furthermore, genetic polymorphisms of enzymes involved in VOCs metabolism will be determined: cytochrome P450-2E1*5, glutathione transferases (T1 and M1), and NQO1*2. RESULTS Exposed children presented the TAC response significantly lower than the control group, while TOS did not differ between the two groups, and a significantly higher OSI (5.23 ± 0.357) was found in exposed children than in the group control (2.62 ± 0.187), 95% CI. In the case of VOC metabolites the children presented a concentration above the biological exposure index established by the ACGIH. The polymorphisms that were determined show a high frequency in our population. Conclusions Our first results show that the exposed population exhibits significantly higher levels of a health risk biomarker such as the OSI, which is of concern since our subjects are children. These data will be analyzed in a multivariate model together with VOC metabolite levels, genetic polymorphisms and other variables, in order to obtain a better picture of the factors affecting this important biomarker (OSI), also, in comparison with a control population.

Environmental exposure to arsenic and chromium in children is associated with kidney injury molecule-1

Environmental hazards from natural or anthropological sources are widespread, especially in the north-central region of Mexico. Children represent a susceptible population due to their unique routes of exposure and special vulnerabilities. In this study we evaluated the association of exposure to environmental kidney toxicants with kidney injury biomarkers in children living in San Luis Potosi (SLP), Mexico. A cross-sectional study was conducted with 83 children (5–12 years of age) residents of Villa de Reyes, SLP. Exposure to arsenic, cadmium, chromium, fluoride and lead was assessed in urine, blood and drinking water samples. Almost all tap and well water samples had levels of arsenic (81.5%) and fluoride (100%) above the permissible levels recommended by the World Health Organization. Mean urine arsenic (45.6ppb) and chromium (61.7ppb) were higher than the biological exposure index, a reference value in occupational settings. Using multivariate adjusted models, we found a dose-dependent association between kidney injury molecule-1 (KIM-1) across chromium exposure tertiles [(T1: reference, T2: 467pg/mL; T3: 615pg/mL) (p-trend=0.001)]. Chromium upper tertile was also associated with higher urinary miR-200c (500 copies/μl) and miR-423 (189 copies/μL). Arsenic upper tertile was also associated with higher urinary KIM-1 (372pg/mL). Other kidney injury/functional biomarkers such as serum creatinine, glomerular filtration rate, albuminuria, neutrophil gelatinase-associated lipocalin and miR-21 did not show any association with arsenic, chromium or any of the other toxicants evaluated. We conclude that KIM-1 might serve as a sensitive biomarker to screen children for kidney damage induced by environmental toxic agents.

Establishment of a reference value for chromium in the blood for biological monitoring among occupational chromium workers.

The concentration of chromium in the blood (CrB) has been confirmed as a biomarker for occupational chromium exposure, but its biological exposure indices (BEIs) are still unclear, so we collected data from the years 2006 and 2008 (Shandong Province, China) to analyze the relationship between the concentration of chromium in the air (CrA) of the workplaces and CrB to establish a reference value of CrB for biological monitoring of occupational workers. The levels of the indicators for nasal injury, kidney (β2 microglobulin (β2-MG)), and genetic damages (8-hydroxy-deoxyguanosine (8-OHdG) and micronucleus (MN)) were measured in all subjects of the year 2011 (Henan Province, China) to verify the protective effect in this reference value of CrB. Compared with the control groups, the concentrations of CrA and CrB in chromium exposed groups were significantly higher (P < 0.05). Positive correlations were found between CrA and CrB in chromium exposed groups (r 2006 = 0.60, r 2008 = 0.35) in the years 2006 and 2008. According to the occupational exposure limitation of CrA (50 μg/m(3), China), the reference value of CrB was recommended to 20 μg/L. The levels of nasal injury, β2-MG, 8-OhdG, and MN were not significantly different between the low chromium exposed group (CrB ≤ 20 μg/L) and the control group, while the levels of β2-MG, 8-OHdG, and MN were statistically different in the high chromium exposed group than that in the control group. This research proved that only in occupational workers, CrB could be used as a biomarker to show chromium exposure in the environment. The recommended reference value of CrB was 20 μg/L.

Assessment of exposure to cadmium, lead, manganese, and nickel in workers from foundries.

In this study, biological exposure indicators were used to assess the exposure of workers to cadmium (Cd), lead (Pb), manganese (Mn), and nickel (Ni) in nonferrous metal smelters. A total of 273 male participants (178 exposed and 95 nonexposed control group), working in nonferrous metal foundries located in southern Brazil, were evaluated based on biological indicators, environmental levels, and different types of work performed by the participants. Blood Pb (BPb), urinary Cd (UCd), urinary Mn (UMn), and urinary Ni (UNi) levels were quantified by graphite furnace atomic absorption spectrometry with Zeeman background correction. Significant differences between the exposed and nonexposed groups were observed for all of the analyzed elements. The average levels of BPb were higher than the recommended occupational exposure level. Relatively low concentrations were found for UCd, UMn, and UNi. Although metal production is an important segment of the Brazilian economy, information related to employee health in this sector is scarce. The environmental levels are determinant in occupational exposure in foundries. In companies where air levels of Pb, Cd, and Mn were above the established limits, the different types of activity did not represent an important influence on the biological levels found among workers. In situations with low air levels of these metals, the workers from the "melting" sector were actually more vulnerable.

Chromium-induced skin damage among Taiwanese cement workers.

Little research has been done on the relationships between chromium exposure, skin barrier function, and other hygienic habits in cement workers. Our purpose was to investigate chromium-induced skin barrier disruption due to cement exposure among cement workers. One hundred and eight cement workers were recruited in this study. Urinary chromium concentration was used to characterize exposure levels. The biological exposure index was used to separate high and low chromium exposure. Transepidermal water loss (TEWL) was used to assess the skin barrier function. TEWL was significantly increased in workers with high chromium exposure levels than those with low chromium exposure levels (p = 0.048). A positive correlation was also found between urinary chromium concentration and TEWL (R = 0.28, p = 0.004). After adjusting for smoking status and glove use, a significant correlation between urinary chromium concentrations and TEWL remained. Moreover, workers who smoked and had a high chromium exposure had significantly increased TEWL compared to nonsmokers with low chromium exposure (p = 0.01). Skin barrier function of cement workers may have been disrupted by chromium in cement, and smoking might significantly enhance such skin barrier perturbation with chromium exposure. Decreased chromium skin exposure and smoking cessation should be encouraged at work.

Method for the Determination of Benzene Metabolite t,t-Muconic Acid in Urine by HPLC-UV with an Ion Exclusion Column

The benzene metabolite trans,trans-muconic acid (tt-MA) is widely used as a biological indicator of exposure to this xenobiotic. An analytical method was developed and validated for the determination of urinary tt-MA using solid phase extraction onto a Strata SAX cartridge. The analysis was performed by HPLC with an Aminex HPX-87H ion exclusion column and a UV diode array detector. The sample preparation conditions were optimized using a 24−1 factorial design. Comparison of the slopes of standard analytical curves prepared in aqueous solution and urine showed that the biological matrix suppressed the tt-MA signal by around 50%, so the analytical curves were prepared with tt-MA standard at low concentrations in pooled urine. The analytical curves in the range of 5–500 μg·L−1 showed determination coefficients values (R2) &gt; 0.99 for tt-MA standard in water and R2 &gt; 0.98 for tt-MA standards in pooled urine. The coefficients of variation obtained using seven replicates were lower than 3.6%, and recoveries of tt-MA from solutions containing 5, 25, 50 and 100 μg·L−1 of the analyte were in the range 85%–90%, demonstrating the satisfactory precision and accuracy of the method. The limits of detection and quantification were 0.11 and 0.36 µg ·L−1, respectively. The benefits of this new method developed is the possibility of complete chromatographic peak separation for the determination of tt-MA at baseline, without matrix components’ interference as normally found in the C18 column. This is the first time that this chromatographic column has been used for the analysis of tt-MA in urine.

Quantitative olfactory disorders and occupational exposure to phenolic resins.

To investigate whether exposure to phenolic resins (PR) is associated with quantitative olfactory disorders (QOD), a cross-sectional study of self-reported olfactory impairment (SROI) was performed in occupationally exposed subjects. Sixty-six workers (45 males, 21 females) at the age (mean ± standard deviation) of 39.8±10.15 years old were divided into 3 exposure groups on the basis of biological exposure indices (BEI) for urinary phenols. It was asked whether the sense of smell has been normal or abnormal during the recent 2 months: the participants were eventually divided into self-reported normosmic, hyposmic, hyperosmic groups. Prevalence of the SROI was 45.5%, with 21 (31.8%) workers complaining about the hyposmia, 12 (18.2%) - anosmia and 9 (13.6%) - hyperosmia. In univariate analyses, female sex was associated with the SROI and the hyperosmia. Highly exposed workers showed the SROI more frequently (odds ratio (OR) = 4.714; 95% confidence interval (CI): 1.077-20.626) than those not exposed (reference) or low exposed (OR = 1.333; 95% CI: 0.416-4.274). In multivariate analyses, female sex was the main risk factor for the SROI (adjusted odds ratio (ORa) = 5.622; 95% CI: 1.525-20.722) and the hyperosmia (ORa = 25.143; 95% CI: 2.379-265.7) but a high exposure to phenol (ORa = 11.133; 95% CI: 1.060-116.9) was the main risk factor for the anosmia. This study has found slight evidence among the cross-section of chemical industry workers that the exposure to phenol may be associated with the SROI. On the other hand, self-reporting of the QOD may be biased by personal factors and further research with objective measurement is therefore required. Med Pr 2016;67(2):173-186.

Hematological Findings in Medical Professionals Involved at Intraoperative Fluoroscopy

&lt;p&gt;Medical professionals involved at intraoperative fluoroscopy are exposed to low doses of the occupational radiation exposures. The biological effects of chronic low-dose radiation on human health are complex and have not been well established. The aim of the present study is to follow up hematological parameter changes during 2 years in medical professionals exposed to ionization radiation in operating rooms.&lt;strong&gt;&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;22 medical professionals (medical specialists and technicians), chronically exposed to ionizing radiation of mobile C-Arm X ray machine, were selected. The seven hematological parameters were examined each time. The statistical analyses were done by Student’s t test and one way ONOVA test.&lt;/p&gt;&lt;p&gt;The data analysis led to the following observations: (1) the present study incorporated that the basic hematological parameters including the mean value of red blood cells (P=0.90), white blood cells (P=0.68), and platelets count (P=0.45) did not show a significant difference between two years. (2) The mean values corpuscular hemoglobin concentration, corpuscular hemoglobin, and hematocrit parameters were found disturbed low or high in some of medical professionals but their means were not significantly different between two measurements. (3)A statistically significant relation in mean value of RBCs with the duration of exposure and sex were observed.&lt;/p&gt;&lt;p&gt;It seems that, hematological parameters survey could not be a reliable test as the biological indicator of long term exposure to very low dose of radiation exposure in medical professionals which their physical dosimetry values are lower than dose limits. &lt;/p&gt;

Effect of Occupational Cadmium Exposure on Parathyroid Gland.

BACKGROUND:Cadmium (Cd) is used in many industries. High-level exposure is associated with severe kidney and bone damage.AIM:This study investigates the possible effect of occupational cadmium exposure on parathyroid gland and some minerals in workers.METHODS:Environmental air monitoring of cadmium was done. Serum and urine cadmium levels, kidney function, some minerals, and plasma parathormone were estimated in the studied groups.RESULTS:The exposed workers had significantly higher Cd concentration in serum and urine than controls. The mean levels of plasma parathyroid hormone, serum phosphorus and magnesium were significantly lower among the exposed group. However, the mean levels of serum creatinine and calcium were significantly higher in the same group when compared to referents. There was a significant positive correlation between Cd concentration in the serum and urine for the exposed group. The biological Cd exposure indices correlated positively with serum calcium and negatively with plasma PTH level. The prevalence of musculoskeletal complaints, bone ache, joint pain and muscle spasm were more prevalent among the exposed workers compared with the controls with odds ratio 4.316, 3.053 and 3.103 respectively.CONCLUSIONS:Occupational cadmium exposure has an adverse effect on PTH level and serum human minerals.

A biological indicator of inorganic arsenic exposure using the sum of urinary inorganic arsenic and monomethylarsonic acid concentrations.

The sum of urinary inorganic arsenic (iAs), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA) concentrations is used for the biological monitoring of occupational iAs exposure. Although DMA is a major metabolite of iAs, it is an inadequate index because high DMA levels are present in urine after seafood consumption. We estimated the urinary iAs+MMA concentration corresponding to iAs exposure. We used data from two arsenic speciation analyses of urine samples from 330 Bangladeshi with oral iAs exposure and 172 Japanese workers without occupational iAs exposure using high-performance liquid chromatography with inductively coupled plasma mass spectrometry. iAs, MMA, and DMA, but not arsenobetaine (AsBe), were detected in the urine of the Bangladeshi subjects. The correlation between iAs+MMA+DMA and iAs+MMA was obtained as log (iAs+MMA) = 1.038 log (iAs+MMA+DMA) -0.658. Using the regression formula, the iAs+MMA value was calculated as 2.15 and 7.5 μg As/l, corresponding to 3 and 10 μg As/m(3) of exposures, respectively. In the urine of the Japanese workers, arsenic was mostly excreted as AsBe. We used the 95th percentile of iAs+MMA (12.6 μg As/l) as the background value. The sum of the calculated and background values can be used as a biological indicator of iAs exposure. We propose 14.8 and 20.1 μg As/l of urinary iAs+MMA as the biological indicators of 3 and 10 μg As/m(3) iAs exposure, respectively.

Environmental risk assessment of toxicity exposure: High-throughput expression profiling

Recently, volatile organic compounds (VOCs) in outdoor air pollution have led to major public health problems and the identification of specific minimally invasive biomarkers for assessing environmental toxicant exposure has become increasingly important. However, research into the human health effects of inhalation exposure to VOCs remains insufficient. Using a microarray based approach, we identified and validated characteristic mRNA expression profiles in the human whole blood of workers exposed to VOCs (toluene, ethylbenzene, and xylene), which were then compared with genomic level expressions in workers not exposed to the toxicants. We surveyed 141 workers working in a chemical production factory, of which 66 were not exposed to VOCs. We identified 4384 characteristic discernible exposure indicator mRNAs for toluene, 1296 for ethylbenzene, and 5821 for xylene. Using these, we were able to discern those subjects from the control group to a higher accuracy, sensitivity, and specificity than when using urinary biomarkers. The results showed that altered levels of mRNA can be a reliable, novel, and minimally invasive biological indicator of occupational exposure to VOCs. Future research directions should consider the adverse effects of exposure to VOCs on epigenetic regulation.

Sheep lymph-nodes as a biological indicator of environmental exposure to fluoro-edenite

A significantly increased incidence of pleural mesothelioma in Biancavilla (Sicily, Italy) has been attributed to exposure to fluoro-edenite (FE), a fibrous amphibole extracted from a local stone quarry.The lymph-nodes draining the pulmonary lobes of sheep grazing around the town were examined, to gain insights into fibre diffusion.The pasture areas of six sheep flocks lying about 3km from Biancavilla were located using the global positioning system. The cranial tracheobronchial and one middle mediastinal lymph-node as well as four lung tissue samples were collected from 10 animals from each flock and from 10 control sheep for light and scanning electron microscopy (SEM) examination.The lymph-nodes from exposed sheep were enlarged and exhibited signs of anthracosis. Histologically, especially at the paracortical level, they showed lymph-follicle hyperplasia with large reactive cores and several macrophages (coniophages) containing grey-brownish particulate interspersed with elements with a fibril structure, forming aggregates of varying dimensions (coniophage nodules). Similar findings were detected in some peribronchiolar areas of the lung parenchyma. SEM examination showed that FE fibres measured 8–41µm in length and 0.4–1.39µm in diameter in both lymph-nodes and lung tissue.Monitoring of FE fibres in sheep lymph-nodes using appropriate techniques can help set up environmental pollution surveillance.