Increased aluminum and lithium and decreased zinc levels in plasma is related to cognitive impairment in workers at an aluminum factory in China: A cross-sectional study.

BACKGROUND: Previous studies have shown that multiple imbalances of metal ions in the brain are closely associated with the neurodegenerative disorders. Our studies have shown that long-term working exposure to aluminum induces increased plasma aluminum levels and causes cognitive impairment in workers at aluminum factories. OBJECTIVE: To explore the levels of nine metals in plasma and the effect on cognitive function among in-service workers. METHODS: In this cross-sectional study, cognitive function was assessed using the Montreal Cognitive Assessment (MoCA), which included seven subitems: executive/visuospatial abilities; naming; attention and calculation; language; abstract; recall; and orientation. The plasma levels of nine kinds of metals were measured by inductively coupled plasma-mass spectrometry (ICP-MS). A multivariate generalized linear regression model and Bayesian kernel machine regression (BKMR) were selected to estimate the relationship between metal plasma level and MoCA scores with adjustment for confounders. RESULTS: One hundred and eighty-seven workers participated in this study. In the multivariable generalized linear model, among these nine metals studied, five were related to the MoCA score: aluminum, lithium, cobalt, zinc and chromium. In the BKMR model, a significantly negative correlation between the plasma aluminum, lithium and the total MoCA score was observed. Moreover, for subitems on the MoCA scale, the plasma levels of lithium, aluminum, and zinc had a significant correlation with the executive/visuospatial abilities, naming, and orientation abilities, respectively. The log-transformation concentrations of plasma aluminum and lithium were negatively correlated with the executive/visuospatial abilities and naming abilities, respectively. The log-transformation plasma zinc concentration was positively correlated with orientation abilities. CONCLUSION: Based on the results, we determined that increased aluminum and lithium and decreased zinc levels in plasma were associated with the incidence of mild cognitive impairment (MCI) in workers at a Chinese aluminum plant.

Cross-sectional study based on occupational aluminium exposure population.

To evaluate the different characteristics of cognitive impairment caused by occupational aluminium exposure at different ages, we surveyed 1660 workers in Shanxi Aluminium Plant, China, and assessed their cognitive function and plasma aluminium concentration. In multiple linear regression, the scores of the digit-span test (DST) and digit-span backward test (DSBT) were negatively correlated with plasma aluminium concentration when concentration reached 34.52 µg/L in younger group (＜40 years), while in the middle-aged group (≥40 years) only found when concentration reached 42.25 µg/L (ß<0, P < 0.05). In logistic regression, when plasma aluminum concentration reached 42.25µg/L, odds ratios (95 % confidence interval) were 1.695 (1.062-2.705) and 3.270 (1.615-6.620) for DST, 7.644 (3.846-15.192) and 15.308 (4.180-56.059) for DSBT in middle-aged group and younger group, respectively. These results showed that aluminium exposures were associated with cognitive impairment among aluminium-exposed workers, particularly for young workers who were more susceptible.

Metabolomic profiling identifies plasma sphingosine 1-phosphate levels associated with welding exposures.

BACKGROUND: Despite a number of known health hazards of welding fume exposure, it is unclear how exposure affects the human metabolome. OBJECTIVE: We assessed the metabolic profiles of welders before and after a 6-hour welding shift, controlling for circadian rhythm of metabolism on a non-welding day. METHODS: Welders were recruited from a training centre in Quincy, Massachusetts, in 2006 and 2010-2012 and donated blood samples on a welding shift day before and after work, as well as on a non-welding day spent in an adjacent classroom. In total, we collected 509 samples from 74 participants. Liquid chromatography-mass spectrometry quantified 665 metabolites from thawed plasmas. Metabolites with significant time (afternoon compared with morning) and day (welding/classroom) interactions were identified by two-way analysis of variance, and the overnight changes were evaluated. RESULTS: Sphingosine 1-phosphate (S1P) and sphingasine 1-phosphate (SA1P) exhibited significant interaction effects between day and time with false discovery rate-adjusted p values of 0.03 and <0.01, respectively. S1P, SA1P and sphingosine shared similar trends over time: high relative levels in the morning of a non-welding day declining by afternoon, but with lower starting levels on a welding day and no decline. There was no obvious pattern related to current smoking status. CONCLUSION: S1P and SA1P profiles were different between welding day and classroom day. The S1P pathway was disrupted on the day of welding exposure. The levels of S1P, SA1P and sphingosine were highly correlated over time. S1P is a signalling lipid with many vital roles; thus, the underlying mechanism and clinical implications of this alteration need further investigation.

[Serum polychlorinated biphenyls in workers of a second-smelting steel mill]. / Policlorobifenili sierici nei lavoratori di una acciaieria di seconda fusione.

SUMMARY: In the steel industry polychlorodibenzodioxins (PCDD), polychlorinated dibenzofurans (PCDF) and polychlorinated biphenyls (PCBs) may be present deriving from the fusion of ferrous and non-ferrous scrap, as well as for the thermal decomposition of the plastic materials (thermoplastic and thermosetting resins) contained therein and not removed before melting at high temperatures. The aim of the study was to assess in 52 workers of a secondmelting steel plant the PCBs exposure deriving from the manual handling of ferrous scrap waste eventually contaminated. The population was divided by production department (scrap, casting and office). Static air sampling of PCDD, PCDF, PCBs and biological monitoring of serum dioxin-like PCBs (DL-PCBs) were performed. The comparison of serum DL-PCB values between workers from the scrap department and those from the casting did not find any statistically significant differences (Mann- Whitney U test). The range of serum DL-PCBs was 7.74-78.55 ng/g lipids with an average of 24.21 ng/g lipids, much lower than the reference values measured in the Italian general population in 2011. Mean and median TEQ WHO 1998 of DL-PCBs were 0.22 pg/g lipids and 0.15 pg/g lipids respectively. The low concentrations of serum DL-PCBS in the studied population can be explained by the progressive reduction of environmental PCBs contamination.

Dermal and inhalable cobalt exposure-Uptake of cobalt for workers at Swedish hard metal plants.

PURPOSE: Cobalt exposure is known to cause adverse effects on health. A major use of cobalt is in the manufacture of hard metal. Exposure can lead to asthma, hard metal lung disease, contact allergy and increased risk of cancer. Cobalt is mainly absorbed from the pulmonary tract, however penetration through skin may occur. The relationships between exposure to inhalable cobalt in air and on skin and the uptake in blood and urine will be investigated, as well as the association between dermal symptoms and dermal exposure. METHODS: Cobalt exposure in 71 workers in hard metal production facilities was measured as inhalable cobalt in the breathing zone and cobalt found on skin with acid wash. Uptake of cobalt was determined with concentrations in blood and urine. Correlations between exposure and uptake were analysed. RESULTS: Inhalable cobalt in air and cobalt in blood and urine showed rank correlations with coefficients 0.40 and 0.25. Cobalt on skin and uptake in blood and urine presented correlation coefficients of 0.36 and 0.17. Multiple linear regression of cobalt in air and on skin with cobalt in blood showed regression coefficients with cobalt in blood (ß = 203 p < 0.0010, and ß = 0.010, p = 0.0040) and with cobalt in urine (ß = 5779, p = 0.0010, and ß = 0.10, p = 0.60). CONCLUSIONS: Our data presents statistically significant correlations between exposure to cobalt in air with uptake of cobalt in blood and urine. Cobalt on skin was statistically significant with cobalt in blood but not with urine.

Occupational metals exposure and cognitive performance among foundry workers using tau protein as a biomarker.

INTRODUCTION: Human exposure to heavy metals is a potential risk for developing cognitive impairment. Aluminum (Al) foundry is one of industries that involve occupational exposure to different metals. AIM OF THE WORK: to evaluate the cognitive performance of Aluminum foundry workers in relation to different metals exposure. MATERIALS AND METHODS: a cross sectional study conducted on 75 Al foundry workers and 75 non-occupationally exposed subjects as controls. Personal interview with specially designed questionnaire, Assessment of cognitive functions done using Montreal cognitive assessment (MocA), Stress, depression and sleep were also assessed. Serum levels of Aluminum (AL), Lead (Pb), manganese (Mn), Zinc (Zn) and tau protein were measured. RESULTS: Exposed group showed significant increase in serum levels of Aluminum, lead, Manganese and tau protein, p value < 0.005 (mean ±â€¯SD 0.56 ±â€¯0.18, 22.3 ±â€¯5.01, 42.04 ±â€¯7.4, 1.53 ±â€¯0.58 Vs 0.36 ±â€¯0.11, 13.4 ±â€¯1.29, 39.4 ±â€¯4.4, 1.03 ±â€¯0.44 respectively) with significant decrease of zinc level compared to control (mean ±â€¯SD 46.4 ±â€¯5.2 Vs 88.8 ±â€¯6.04, p value 0.005). There was a significant decrease MocA scores among exposed population, (mean ±â€¯SD 24.4 ±â€¯3.4 compared to 28.4 ±â€¯1.3 in non exposed, p value < 0.005). which was affected by serum levels of lead, aluminum, manganese and tau protein (ß -0.165, -8.958, -.286, -2.341 respectively and p < 0.005).Stress scores was higher in exposed workers than control but not affecting cognitive performance. CONCLUSION: occupational exposure to metals can cause cognitive dysfunction which may be subtle, so there is a need for formal cognitive testing at baseline, and on regular intervals during working period. Serum tau protein could be used as a prognostic biomarker for the hazardous effect of occupational exposure to these metals on the neuronal cells.

Serum levels of polychlorinated biphenyls and risk of non-Hodgkin lymphoma: A hospital-based case-control study.

Polychlorinated biphenyls (PCB) have been classified by the International Agency for Research on Cancer (IARC) in Group 1 as carcinogenic to human, based on sufficient evidence in humans of an increased risk of cutaneous malignant melanoma and limited evidence for non-Hodgkin lymphoma (NHL). However present findings on the association of PCB exposure and NHL are still controversial. This study examined the relationship between PCB serum levels and risk of NHL in a Northern Italy area (Brescia province), where a chemical factory produced PCBs from 1938 to 1984, causing human contamination. A case-control study of 215 NHL patients and 215 control subjects was conducted. Cases and controls were assayed for serum levels of 33 PCB congeners. No associations were found between risk of NHL and serum levels of total PCBs (OR = 0.51; 95% CI: 0.25-1.04 for highest vs lowest quartile) or specific PCB congeners. The study confirmed a strong association of NHL with HCV infection (OR = 3.60; 95% CI: 1.30-10.02). This case-control study does not support the hypothesis of an association between current serum levels of PCBs and NHL development in the general population.

lncRNAVNN3 mediated benzene-induced hematotoxicity through promoting autophagy and apoptosis.

The potential toxicity of low-dose benzene exposure to human health has received attention, but the mechanisms of low-dose benzene-induced hematotoxicity remain largely unknown. The purpose of our study was to investigate the relationships between lncRNAVNN3 expression with benzene-induced autophagy and apoptosis in control and benzene-exposed workers. Seventy benzene-exposed workers and seventy non-benzene-exposed healthy workers were recruited. The expression of lncRNAVNN3, serum autophagy-associated and apoptosis-associated proteins were evaluated, and the relationship among them were also analysed. Furthermore, the mechanism of lncRNAVNN3 on autophagy and apoptosis induced by benzene metabolite (1, 4-benzoquinone, 1, 4-BQ) was investigated in vitro. The results showed that the expression of lncRNAVNN3 increased in benzene-exposed workers (p < 0.05). A positive correlation was found between lncRNAVNN3, serum autophagy-associated and apoptosis-associated proteins. In addition, we found that the knockdown of lncRNAVNN3 reduced phosphorylation of beclin1 and Bcl-2, which mediated 1, 4-benzoquinone-induced autophagy and apoptosis. Overall, lncRNAVNN3 mediated 1, 4-benzoquinone-induced autophagy and apoptosis though regulating phosphorylation of beclin1 and Bcl-2, suggesting that lncRNAVNN3 might be a novel early sensitive biomarker of benzene-induced hematotoxicity.

Investigation of occupational exposure to lead and its relation with blood lead levels in electrical solderers.

Occupational exposure to lead compounds can cause headache, nausea, encephalopathy, anemia, chronic muscle pain, and saturnism. Exposure to lead in women can affect fertility, and cause abortion or low IQ in the offspring. The aim of this study was to investigate occupational exposure to lead and its relation with blood lead levels in female electrical parts solderers. This cross-sectional (descriptive and analytical) study was carried out on 40 female solderers, working in two electrical parts manufacturing factories in Neyshabur city in 2017-2018. Occupational exposure to lead was determined by the OSHA 121 method, and the NIOSH 8003 method was used to determine the concentration of lead in blood. Lead in blood and air samples were determined by using a flame atomic absorption analyzer. Blood was measured using a Cell Dyn Hematology device. Data were analyzed using STATA 15. The mean age of the solderers was 35.42 ± 6.80 years, and their average work experience was 7.85 ± 5.60 years. Mean occupational exposure to lead was 0.09 ± 0.01 mg/m3, and the mean levels of lead in the blood of solderers were 10.59 ± 3.25 µg/dL. The mean of red blood cells (RBC) was 4.88 mil/uL, white blood cells (WBC) = 8.53 Tho/uL, hemoglobin = 14.02 g/dL, and hematocrit = 42.38%. There was a significant correlation between the concentrations of lead in air and the level of lead in workers' blood (p = 0.012, r = 0.31). The level of lead in the workers' respiratory region (ß = 0.36, p = 0.033), body mass index (ß = 0.25, p = 0.028), and the season of the year (ß = 0.21, p = 0.019) were the strongest factors affecting blood lead levels. There was a significant relation between lead in workers' air and their blood, although all blood indices were in normal range. Using lead-free alloys and local ventilation systems, and reducing exposure times are recommended to decrease exposure to lead among solderers.

[Study on the health effects of occupational exposure to low concentrations of benzene].

Objective: The main purpose of this study was to ascertain whether (or not) exposure to benzene, toluene, xylene and ethylbenzene (BTXE) , under normal working conditions, was associated with any health effects. Methods: From January to December 2014, the workplaces concentrations of BTXE were measured of 71 enterprises in Suzhou Industrial Park. Occupational health examination were investigated on 764 employees who exposed to BTXE, as well as 4409 employees of the corresponding enterprises who unexposed to BTXE, and analyzed the data of the two groups. Results: A total of 6 monitoring sites in 3 enterprises BTXE concentrations excess of the standards, the unexposed group was under the limit of detection. The means of red blood cell count, hemoglobin, hematocrit, intermediate cell count and percentage of intermediate cells were significantly higher in exposed group than in unexposed group (P<0.05) . Conversely, platelet count was significantly lower in exposed group than in unexposed group (P<0.05) . The proportion of red blood cell volume, lymphocyte count and percentage of intermediate cells were significantly lower in exposed group than in unexposed group (P<0.05) . Both means and proportion of glutamic pyruvic transaminase and urea nitrogen were significantly higher in exposed group than in unexposed group (P<0.05) . The positive rate of protein, urine, urine red blood cell were significantly higher in exposed group than in unexposed group (P<0.05) . The abnormal rate of electrocardiogram, liver and kidney B scan were significantly higher in exposed group than in unexposed group (P<0.05) . Multivariate logistic regression analysis revealed that percentage of intermediate cells increased, urea nitrogen increased, urine protein positived, urine red blood cells positived in exposed group the OR values were 1.689, 3.291, 3.163 and 1.743 (P<0.05) . Conclusion: Occupational exposure to low concentrations of BTXE had a certain impact on the blood system and liver and kidney function of the employees, occupational health surveillance for such people should be strengthened.

Validity of different biomonitoring parameters for the assessment of occupational exposure to N,N-dimethylformamide (DMF).

This study was performed to assess the relation between occupational exposure to N,N-dimethylformamide after an 8 h work shift in the acrylic fibre industry and its three biological markers N-methylformamide (NMFtotal), N-acetyl-S-(N-methylcarbamoyl)cysteine (AMCC), and N-methylcarbamoyl adduct at haemoglobin (MCVal). External DMF exposure of 220 workers was determined during the whole shift. A standardised questionnaire was used to obtain information about the worker's general health status, medical treatment, smoking habits, protective measures, and possible symptoms caused by DMF exposure. NMF and AMCC were analysed in post-shift urine samples and MCVal in blood. For longitudinal assessment the average AMCC concentration was determined over a period of 4 weeks (weekly sampling) in a sub-collective of 89 workers. The median of DMF concentration in air was 3.19 mg/m3 (range < 0.15-46.9 mg/m3). The biological markers showed a median of 4.80 mg/L (range 0.20-50.6 mg/L) for NMFtotal, 4.75 mg/g creatinine (range 0.06-49.6 mg/g creatinine) for AMCC, and 57.5 nmol/g globin (range 0.5-414 nmol/g) for MCVal. A significant linear relationship was observed between DMF in air and NMF as well as between DMF in air and AMCC in post-shift urine samples. The mean AMCC values measured weekly over a period of 4 weeks correlated significantly with MCVal adducts too. Excluding workers who had been using breathing masks on the day of the study led to even tighter correlations. The results of the present study demonstrate the applicability of the DMF biomonitoring parameters NMFtotal in post-shift urine for the present-day exposure assessment, AMCC in the post-shift urine after several shifts for assessment of the cumulative exposure of the previous working days, and MCVal for assessment of long-term exposure during previous weeks and months. The data of the present study enable now the estimation of valid equivalents of these biomonitoring parameters to the external DMF exposure. From the risk assessment point of view, the exposure limit values for AMCC and MCVal, which are directly linked to the presumed toxic intermediate MIC, exhibit a significant advance.

Occupational exposure to asphalt fume can cause oxidative DNA damage among road paving workers.

OBJECTIVES: We designed the present study to determine the effect of occupational exposure to asphalt fumes on oxidative status and DNA damage in road paving workers. METHODS: Sixty road paving workers exposed to asphalt fumes and forty non-exposed control subjects were recruited. Occupational exposure to PAHs was assessed by urinary 1-hydroxypyrene (1-OHP) excretion. Serum thiol disulfide homeostasis (TDH), total oxidant status (TOS) and total antioxidant status (TAS) and urinary 8-hydro-deoxyguanosine (8-OH-dG) level were evaluated by automated colourimetric method. RESULTS: The urinary concentrations of 1-OHP and 8-OH-dG were significantly higher in the exposed group than in the control group (P < 0.001). Disulfide/thiol ratio, TOS, and TAS were also significantly higher for the asphalt workers. A positive correlation existed between urinary 1-OHP and 8-OH-dG, TOS and TAS. CONCLUSION: Study results indicate that exposure to PAHs induces oxidative stress and causes genotoxic effects in asphalt workers.

Effects of occupational exposure to aluminium on some oxidative stress and DNA damage parameters.

AIM: The aim of this work was to investigate the relationships between aluminium levels, oxidative status and DNA damage in workers occupationally exposed to aluminium. SUBJECTS AND METHODS: This study was conducted in a secondary aluminium smelter. It included 96 male workers occupationally exposed to aluminium fume and dust compared to 96 male nonexposed individuals. Full history and clinical examination were done for all participants. Laboratory investigations in the form of serum aluminium, total antioxidant capacity (TAC), urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) and comet assay test were performed. RESULTS: Serum aluminium level ranged from 4 to 30 µg/L of median: 10 µg/L; urinary 8-OHdG ranged from 2.7 to 17.2 ng/mg creatinine of median: 7.6 ng/mg creatinine; comet tail length (CTL) ranged from 19.7 to 50.5 µm of median: 45 µm, were statistically significantly increased in the exposed group compared to nonexposed group. In exposed workers, a statistically significant positive correlations were found between serum aluminium level and urinary 8-OHdG ( r = 0.75, p < 0.001); aluminium level and CTL ( r = 0.71, p < 0.001); and urinary 8-OHdG and CTL ( r = 0.71, p < 0.001). There was a statistically significant negative correlation between serum aluminium and TAC ( r = -0.76, p < 0.001). CONCLUSION: Occupational exposure to aluminium in secondary aluminium smelters was related to the induction of oxidative stress and DNA damage. This may promote the development of adverse health hazards in the exposed workers.

The risk of occupational exposure to mercury vapor in some public dental clinics of Baghdad city, Iraq.

BACKGROUND: Dental workers are exposed to elevated levels of elemental mercury vapor substantially above the occupational exposure standards when placing or removing mercury/silver tooth restorations and disposing of mercury waste. This results in a significant increase in occupational exposure and risk of mercury intoxication. METHODS: To evaluate the occupational exposure of dental workers to amalgam in four dental clinics in Baghdad city, the concentrations of mercury vapor were measured seasonally from February to November 2016. Samples of blood and urine were collected from 30 dental workers (exposed individuals) and five non-occupationally exposed individuals. Biochemical parameters such as cholesterol, liver enzymes (alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase), renal enzymes (urea and creatinine), total protein and reduced glutathione (GSH) were observed. RESULTS: The results indicated that mercury vapor levels varied from 84.7 ± 18.67 to 609.3 ± 238.90 µg/m3 and most concentrations were above the occupational exposure standards. The results of the biochemical parameters showed a significant increase in levels of cholesterol, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) and no significant increase in blood urea and creatinine in dental workers in comparison with unexposed persons (control). Although the results showed a significant reduction in the levels of glutathione and total protein, there was no significant decrease in the levels of alkaline phosphatase (ALP) in exposed dental workers when compared with non-occupationally exposed individuals. CONCLUSIONS: It is concluded that mercury vapor concentrations in the indoor air of some dental clinics in Baghdad city are high and exceed the OSHA STEL(Occupational Safety and Health Administration Short Term Exposure Limit). The present data showed that altered biochemical parameters can be used as efficient bioindicators for mercury toxicity.

Correlation between airborne manganese concentration at the workstations in the iron foundry and manganese concentration in workers' blood.

BACKGROUND: Manganese (Mn) used as raw material for melting process in the ferrous foundry is considered as hazardous neurotoxic substance because it accumulates in the central nervous system and may cause neurological disorders. The furnace-men and melting department workers are potentially exposed to manganese particles or fume in the workplace. The objective of the research has been to investigate the sources and levels of manganese exposure in the foundry by correlation of blood-manganese (B-Mn) and air-manganese (air-Mn) measurement. MATERIAL AND METHODS: Air-Mn and Mn of blood serum were measured involving workers who worked in a big-sized foundry during 1 year. The standard method of the Occupational Safety and Health Administration (OSHA) ID-121 was used for air and blood assessment and atomic absorption spectroscopy (AAS) was carried out for air and blood sample analysis. RESULTS: The air sampling results have revealed that there is a high exposure to manganese (4.5 mg/m3) in the workplace as compared to the National Institute for Occupational Safety and Health's (NIOSH) time weighted average (the reference time-weighted average (TWA) = 1 mg/m3). The average blood serum Mn concentration was 2.745 µg/l for subjects working for shorter than 3 months and 274.85 µg/l for subjects working 3-12 months. CONCLUSIONS: Against the research hypothesis there was no correlation between the air-Mn concentration and the B-Mn (serum) level of manganese in the serum of the exposed subjects. It may be due to short time of air sampling of manganese airborne particles, and a real-time monitoring of airborne manganese particles is suggested for any future study. Med Pr 2017;68(4):449-458.

Do polychlorinated biphenyls cause cancer? A systematic review and meta-analysis of epidemiological studies on risk of cutaneous melanoma and non-Hodgkin lymphoma.

In 2015 a IARC Working Group upgraded the classification of PCBs to Group 1 "Carcinogenic to humans", also on the basis of evidence from epidemiological studies showing an excess risk for melanoma. Increased risks for non-Hodgkin lymphoma (NHL) and breast cancer were also reported though the evidence was limited. However, some recent reviews of studies on PCB exposure and risk of cancer provided discrepant findings. Therefore, we re-evaluated the association between exposure to PCBs and risk of melanoma and NHL by a systematic review and meta-analysis. We retrieved 11 independent cohort studies on occupationally exposed workers. About half of them showed increased standardized mortality or incidence ratios (SMRs or SIRs) for melanoma and none for NHL. The pooled SMRs were 1.32 (95% CI: 1.05-1.64) for melanoma and 0.94 (0.73-1.23) for NHL. Among population-based cohort and case-control studies with individual measures of PCB exposure, one only study was carried out on PCB exposure and melanoma, showing an odds ratio (OR) of 6.0 (2.0-18.2) for the highest compared to lowest quartile of PCB distribution. 13 cohort and case-control studies evaluated the association between NHL and PCB concentration in blood or subcutaneous fat, with summary OR = 1.5 (1.1-1.7) for the highest vs lowest quantile of PCB distribution. However, two cohort studies on people intoxicated by rice oil containing PCBs found no excess of deaths for skin cancer and inconsistent results for NHL. In conclusion, these findings do not provide a strong evidence that PCB exposure can increase the risk of melanoma and NHL in humans.

Occupational exposure to PCDDs, PCDFs, and DL-PCBs in metallurgical plants of the Brescia (Lombardy Region, northern Italy) area.

The concentration values of polychlorodibenzodioxins (PCDDs), polychlorodibenzofurans (PCDFs), and dioxin-like polychlorobiphenyls (DL-PCBs) in blood serum samples (pools) of metallurgical workers in the area of the city of Brescia (northern Italy) were statistically processed. As to workers' exposure characteristics, pools were divided into 34 professionally exposed (PE) and 11 non-professionally exposed (NPE). A further subdivision of PE pools was according to workplaces in which ferrous (N = 24) and non-ferrous (N = 10) materials were handled. To evaluate the aforesaid differences we applied the age-adjusted Generalized Linear Models. We identified significant (P ≤ 0.05) exposure models of the classification groups. The first subdivision was confirmed by the concentrations of 1,2,3,4,6,7,8-H7CDF, DL-PCB 105, and DL-PCB 189; the second was confirmed by the concentrations of PCDF TEQ97, PCDD + PCDF + DL-PCB (TEQTOT) TEQ97, 2,3,4,7,8-P5CDF, 1,2,3,6,7,8-H6CDD, 1,2,3,4,6,7,8-H7CDD, and PCB 189. Based on the literature, all mentioned congeners have been found in stack gas and fly ash samples of metallurgical plants: therefore, these indicators indicate the exposure to such work environments. Specifically, the concentrations measured in the workers' blood serum appear to depend on the type of material processed during work.

Occupational Exposure to Indium of Indium Smelter Workers.

Case reports of indium-related lung disease in workers have raised public concern to the human toxicity of indium (In) and its compounds. However, studies evaluating the exposure or health of workers in In smelting plants are rare. Therefore, in this study, we focused on four In smelting plants, with the main objective of characterizing In in smelter plants in China and discussing the potential exposure biomarkers of In exposure. We recruited 494 subjectsat four In smelting plants in China. Personal air samples, first morning urine and spot blood samples were collected. In concentrations in samples were analyzed using inductively coupled plasma mass spectrometry. In concentrations in air samples did not exceed the permissible concentration-time weighed average, but the smelter workers had a higher internal exposure to In. Positive correlations were observed between the air In and urine In concentrations, and between the air In and blood In concentrations. This study provides basic data for the following In exposure and health risk assessment.

Blood morphology and the levels of selected cytokines related to hematopoiesis in occupational short-term exposure to lead.

The aim of the study was to investigate the influence of a short-term exposure to lead on the blood morphology and the levels of selected cytokines related to hematopoiesis in occupationally exposed workers. The study population included 37 males occupationally exposed to lead for 36 to 44days. Their blood lead level raised from 10.7±7.67µg/dl at baseline to the level of 49.1±14.1µg/dl at the end of the study. The level of hemoglobin and values of MCH and MCHC were decreased due to a short-term exposure to lead by 2%, 2%, and 1%, respectively. The counts of WBC, LYM, and MXD increased significantly by 5%, 7%, and 35%. Similarly, the count of PLT increased by 7%, while PDW, MPV, and P-LCR decreased by 6%, 3%, and 9%, respectively. The levels of IL-7, G-CSF, HGF, PDGF AB/BB, SCF, and PECAM-1, decreased significantly by 30%, 33%, 8%, 30%, 25%, and 20%, respectively. A short-term occupational exposure to lead results in a decreased hemoglobin level and increased counts of WBC and PLT. Changes in counts and proportions of different types of leukocytes and decreased values of PLT indices, such as PDW, MPV, and P-LCR, due to the subacute lead-exposure may be associated with lead-induced decreased levels of cytokines related to hematopoiesis, including SCF, G-CSF, IL-7, and PDGF.

Dose-Response Relationship between Cumulative Occupational Lead Exposure and the Associated Health Damages: A 20-Year Cohort Study of a Smelter in China.

Long-term airborne lead exposure, even below official occupational limits, has been found to cause lead poisoning at higher frequencies than expected, which suggests that China's existing occupational exposure limits should be reexamined. A retrospective cohort study was conducted on 1832 smelting workers from 1988 to 2008 in China. These were individuals who entered the plant and came into continuous contact with lead at work for longer than 3 months. The dose-response relationship between occupational cumulative lead exposure and lead poisoning, abnormal blood lead, urinary lead and erythrocyte zinc protoporphyrin (ZPP) were analyzed and the benchmark dose lower bound confidence limits (BMDLs) were calculated. Statistically significant positive correlations were found between cumulative lead dust and lead fumes exposures and workplace seniority, blood lead, urinary lead and ZPP values. A dose-response relationship was observed between cumulative lead dust or lead fumes exposure and lead poisoning (p < 0.01). The BMDLs of the cumulative occupational lead dust and fumes doses were 0.68 mg-year/m³ and 0.30 mg-year/m³ for lead poisoning, respectively. The BMDLs of workplace airborne lead concentrations associated with lead poisoning were 0.02 mg/m³ and 0.01 mg/m³ for occupational exposure lead dust and lead fume, respectively. In conclusion, BMDLs for airborne lead were lower than occupational exposure limits, suggesting that the occupational lead exposure limits need re-examination and adjustment. Occupational cumulative exposure limits (OCELs) should be established to better prevent occupational lead poisoning.