Health risk in transport workers. Part II. Dietary compounds as modulators of occupational exposure to chemicals.

Professional drivers are exposed to a number of factors that have a negative influence on their health status. These include vibrations, noise, the lack of fresh air in the car cabin, shift work (frequently at night), monotony resulting from permanent repetition of certain actions, static loads due to immobilization in a sitting position, stress resulting from the need to ensure safety in heavy traffic, as well as air pollution (dust, volatile organic substances, nitrogen and sulfur oxides, polycyclic aromatic hydrocarbons, heavy metals, dioxins, furans and others). Factors associated with the specificity of the profession of a driver, including exposure to chemical substances, result in an increased risk of the development of many diseases, i.e., obesity, diabetes, heart disease, hypertension, extensive genitourinary pathology experienced by taxi drivers, lung cancer and other forms of cancer. In the case of drivers, especially those covering long distances, there are also actual difficulties related to ensuring a proper diet. Although attempts at interventional research that would change the principles of nutrition, as well as ensure physical activity and weight reduction, have been made, their results have not been satisfactory. The paper focuses on the discussion on the role of a diet and dietary phytochemicals in the prevention of adverse health effects of such chemicals as a mix of chemicals in the polluted air, benzo(a)pyrene, benzene and metals (lead, cadmium, chromium, nickel), which are the main sources of exposure in the case of transport workers. Int J Occup Med Environ Health. 2019;32(4):441-64.

Response of a novel selenium-dependent glutathione peroxidase from thick shell mussel Mytilus coruscus exposed to lipopolysaccharide, copper and benzo[α]pyrene.

Glutathione peroxidase (GPx) plays an important antioxidant role in cellular defense against environmental stress. In the present study, a novel selenium-dependent glutathione peroxidase termed McSeGPx firstly identified in thick shell mussel Mytilus coruscus. McSeGPx consists of 197 amino acid residues, characterized with one selenocysteine residue encoded by an opal stop codon TGA, one selenocysteine insertion sequence (SECIS) in the 3' untranslated region (UTR), two active site motifs and one signature sequence motif. McSeGPx transcripts were constitutively expressed in all examined tissues, and were significantly induced in gills and digestive glands with the stimulations of lipopolysaccharide (LPS), copper (Cu) and benzo[α]pyrene (B[α]P). Additionally, rough increases in McSeGPx activity were detected in both tissues under the challenge of LPS, Cu and B[α]P. Collectively, these results suggested that McSeGPx affiliate to selenocysteine dependent GPx (SeGPx) family and might play an important role in mediating the environmental stressors and antioxidant response in M. coruscus.

Comparative oesophageal cancer risk assessment of hot beverage consumption (coffee, mate and tea): the margin of exposure of PAH vs very hot temperatures.

BACKGROUND: Consumption of very hot (> 65 °C) beverages is probably associated with increased risk of oesophageal cancer. First associations were reported for yerba mate and it was initially believed that high content of polycyclic aromatic hydrocarbons (PAH) might explain the risk. Later research on other beverage groups such as tea and coffee, which are also consumed very hot, found associations with increased risk of oesophageal cancer as well. The risk may therefore not be inherent in any compound contained in mate, but due to temperature. The aim of this study was to quantitatively assess the risk of PAH in comparison with the risk of the temperature effect using the margin of exposure (MOE) methodology. METHODS: The human dietary benzo[a]pyrene (BaP) and PAH4 (sum of benzo[a]pyrene, benzo[a]anthracene, chrysene, and benzo[b]fluoranthene) exposure through consumption of coffee, mate, and tea was estimated. The oesophageal cancer risk assessment for both PAH and temperature was conducted using the MOE approach. RESULTS: Considering differences in the transfer of the PAH from the leaves of mate and tea or from the ground coffee to the infusion, and considering the different preparation methods, exposures may vary considerably. The average individual exposure in µg/kg bw/day arising from consumption of 1 cup (0.2 L) of infusion was highest for mate (2.85E-04 BaP and 7.22E-04 PAH4). The average per capita exposure in µg/kg bw/day was as follows: coffee (4.21E-04 BaP, 4.15E-03 PAH4), mate (4.26E-03 BaP, 2.45E-02 PAH4), and tea (8.03E-04 BaP, 4.98E-03 PAH4). For all individual and population-based exposure scenarios, the average MOE for BaP and PAH4 was > 100,000 independent of beverage type. MOE values in this magnitude are considered as a very low risk. On the contrary, the MOE for the temperature effect was estimated as < 1 for very hot drinking temperatures, corroborating epidemiological observations about a probable oesophageal cancer risk caused by this behaviour. CONCLUSIONS: The temperature effect but not PAH exposure may pose an oesophageal cancer risk. Consumer education on risks associated with consumption of 'very hot' beverages and policy measures to threshold serving temperatures should be discussed.

Cigarette smoking, coffee drinking, and ingestion of charcoal-broiled beef as potential modifiers of drug therapy and confounders of clinical trials.

A pathway of research is described, leading from the finding of an inhibitory effect of 3-methylcholanthrene on the carcinogenicity of an aminoazo dye, to the induction of drug-metabolizing enzymes by 3-methylcholanthrene, benzo[a]pyrene, and other polycyclic aromatic hydrocarbons, to the demonstration of enhanced drug metabolism in cigarette smokers, coffee drinkers, and people who eat charcoal-broiled beef. The results of these studies indicate that cigarette smoking, coffee drinking, and the ingestion of charcoal-broiled beef (all resulting in exposure to polycyclic aromatic hydrocarbons) can influence the dosing regimen needed for proper drug therapy and are potential confounders of clinical trials with drugs metabolized by polycyclic aromatic hydrocarbon-inducible enzymes.

Evaluation of antigenotoxic effects of carotenoids from green algae Chlorococcum humicola using human lymphocytes.

OBJECTIVE: To identify the available phytochemicals and carotenoids in the selected green algae and evaluate the potential genotoxic/antigenotoxic effect using lymphocytes. METHODS: Organic solvent extracts of Chlorococcum humicola (C. humicola) were used for the phytochemical analysis. The available carotenoids were assessed by HPLC, and LC-MS analysis. The genotoxicity was induced by the benzo(a)pyrene in the lymphocyte culture, the genotoxic and antigenotoxic effects of algal carotenoids with and without genotoxic inducer were evaluated by chromosomal aberration (CA), sister chromatid exchange (SCE) and micronucleus assay (MN). RESULTS: The results of the analysis showed that the algae were rich in carotenoids and fatty acids. In the total carotenoids lutein, ß-carotene and α-carotene were found to be present in higher concentration. The frequency of CA and SCE increased by benzo(a)pyrene were significantly decreased by the carotenoids (P<0.05 for CA, P<0.001 for SCE). The MN frequencies of the cells were significantly decreased by the treatment with carotenoids when compared with the positive controls (P<0.05). CONCLUSIONS: The findings of the present study demonstrate that, the green algae C. humicola is a rich source of bioactive compounds especially carotenoids which effectively fight against environmental genotoxic agents, the carotenoids itself is not a genotoxic substance and should be further considered for its beneficial effects.

Quercetin supplementation suppresses the secretion of pro-inflammatory cytokines in the lungs of Mongolian gerbils and in A549 cells exposed to benzo[a]pyrene alone or in combination with ß-carotene: in vivo and ex vivo studies.

In vitro studies have shown that quercetin modulates the effects of ß-carotene induced by stimulants. Whether these reactions happen in vivo, however, is unclear. Thus, we investigated whether quercetin supplementation suppresses the harmful effects of benzo[a]pyrene (BaP) alone or combined with ß-carotene in the lungs of Mongolian gerbils. The gerbils were given quercetin (100 mg/kg body wt, 3 times/week), ß-carotene (10 mg/kg body wt, 3 times/week), and BaP (8 mmol, 2 times/week) alone or in combination by gavage for 6 months. ß-Carotene supplementation enhanced the pro-inflammatory effects of BaP in the lungs of gerbils. In contrast, quercetin supplementation significantly decreased the infiltration of inflammatory cells as well as the levels of TNF-α and IL-1ß in the bronchoalveolar lavage fluid and plasma of gerbils exposed to BaP or BaP+ß-carotene (P<.05). Such effects of quercetin supplementation were accompanied by a down-regulation of the expression of phospho-c-Jun and phospho-JNK induced by BaP or BaP+ß-carotene in the lungs of gerbils. Furthermore, in the ex vivo study, we found that quercetin-metabolite-enriched plasma (QP) obtained from gerbils acted like a JNK inhibitor to significantly suppress the secretion of pro-inflammatory cytokines induced by BaP or BaP+ß-carotene in A549 cells (P<.05). QP also suppressed the activation of the JNK pathway in the A549 cells. These results suggest that supplemental quercetin suppress the pro-inflammatory effect of ß-carotene induced by BaP in vivo and ex vivo. The regulation of the JNK pathway by the metabolites of quercetin contributes, at least in part, to such effects of quercetin in vivo.

Anticancer potentials of root extract of Polygala senega against benzo[a]pyrene-induced lung cancer in mice.

OBJECTIVE: To evaluate anticancer potentials of Polygala senega on lung cancer induced by benzo[a]pyrene (B[a]P) in mice. METHODS: Swiss albino mice were divided into five groups with each containing six animals. Group 1 served as control, and the animals received olive oil as vehicle. Group 2 animals were treated with B[a]P (50 mg/kg body weight dissolved in olive oil) orally twice a week for four consecutive weeks. Group 3 animals were fed B[a]P as in group 2 and 48% alcohol (since the vehicle of the remedy was alcohol). Group 4 animals were B[a]P-intoxicated mice (as in group 2) which were additionally fed ethanolic extract of Polygala senega (EEPS) daily for 16 weeks. EEPS treatment started after the first dose of B[a]P. Group 5 animals were treated with EEPS alone for 16 weeks to test cytotoxicity of EEPS if any. Mice were sacrificed after 16 weeks and the following parameters were assessed: the anti-oxidant activity measured by 2,2-diphenyl-1-picrylhydrazyl free radical assay, tumor incidence, lung weight and body weight, DNA damage evaluation by comet assay and enzyme-linked immunosorbent assay (ELISA); toxicity biomarkers like catalase, superoxide dismutase, glutathione peroxidase, glutathione reductase, lipid peroxidation (LPO) and total thiol content were also detected. RESULTS: Treatment with EEPS increased the final body weight and significantly decreased the lung weight in group 4 mice (P<0.01) compared with group 3 mice. Comet assay showed that EEPS-treated mice in group 4 presented a decrease of DNA damage significantly (P<0.01) in lung tissues. There was a significant increase observed in the level of p53 in group 4 as compared with group 3 (P<0.01) detected by ELISA. A highly significant increase in tissue LPO with concomitant decrease in the activity of anti-oxidants was observed in group 2 and group 3 mice (P<0.05) compared with the control mice. These adverse changes were reversed significantly in group 4 mice (P<0.01). CONCLUSION: Chemopreventive potentials of Polygala senega against chemically induced lung cancer in mice are confirmed.

[The role of mutation of gene cyp1A1 and benzapilene in cytogenetic changes of urinary tract epitheliocytes in oil industry workers employed in the oil fields of the North of West Siberia].

The examination of 477 oil industry workers and office personnel (control) employed in the oil fields of the North of Tomsk and Tyumen regions has detected increased number of epithelyocytes with micronuclei and an elevated urine level ofbenzapilene in workers employed in oil production. Especially pronounced changes of the above parameters were observed in men with mutant alleles Val of CYP1A1 gene. An enhanced mutation process in oil production workers may be due to a resultant action of different factors on human genome. Involved may be both mutagens and factors of comutagenic nature. The results obtained in this study suggest a conclusion about urgent need of introduction of new scientifically validated criteria of selection of personnel for oil production in the North of the West Siberia. Health examination of the applicants must include genotyping.

In vivo protective effect of crocetin on benzo(a)pyrene-induced lung cancer in Swiss albino mice.

The objective of this investigation was to determine the efficacy of crocetin in preventing lung tumorigenesis in mice. We evaluated crocetin in Swiss albino mice treated with the tobacco-specific carcinogen benzo(a)pyrene [B(a)P] for their ability to inhibit pulmonary adenoma formation and growth. Male Swiss albino mice (7 weeks old) were given 100 mg/kg B(a)P by i.p. injection, and 4 or 14 weeks later, they were given crocetin 50 mg/kg by i.p. injection 3 days/week. Crocetin (50 mg/kg body weight) reduced proliferating cells by 68% and 45% in 18 and 8 weeks of treatment respectively. The levels of glycoproteins and polyamines were significantly altered in the B(a)P-induced animals than in crocetin treatment groups. The activity of crocetin was more pronounced in the cancer. Taken together, these results indicate that crocetin was capable of inhibiting proliferation cells by inhibiting proliferating cells, glycoprotein and polyamine synthesis.

Diagnostic relevance of the determination of lymphocyte subpopulations in environmental medicine.

Earlier hopes that determination of lymphocyte subpopulations might become a strong diagnostic tool in environmental medicine have not been fulfilled in recent years. Analysis of the scientific literature rather shows that there are only few examples for environmental exposures causing reproducible shifts of lymphocyte subpopulations. Moreover, current knowledge suggests that "environmental diseases" are not associated with characteristic changes of subpopulation patterns. If lymphocyte subpopulations are analyzed, each diagnostic step, including indication, sample handling, analytic procedure and data-interpretation, should adhere to good quality criteria. Taking all together, the determination of lymphocyte subpopulations in the context of environmental medicine comes under category IV of the criteria of the Commission for Methods and Quality Assurance in Environmental Medicine of the German federal health authority (Robert Koch-Institute; RKI): "A procedure cannot be recommended because there is not sufficient information to justify it" (here: no solid trends in epidemiological examinations), "and because theoretical considerations speak against an application" (here: high physiological variability and missing exposure or substance specificity).

Cancer risks among iron and steel workers in Anshan, China, Part II: Case-control studies of lung and stomach cancer.

Nested case-control interview studies of lung cancer (610 incident cases), stomach cancer (292 incident cases), and 959 controls were conducted to follow up leads from a proportional mortality analysis of deaths among male workers in a large integrated iron-steel complex in Anshan, China. For lung cancer, after adjusting for the significant non-occupational risk factors (smoking, other pulmonary disease, family history of lung cancer, and low consumption of fruit or tea), risks were significantly elevated for those employed for 15 or more years in smelting and rolling (OR = 1.5, CI = 1.1-2.2), in the fire-resistant brick factory (OR = 2.9, CI = 1.4-5.9), in general loading (OR = 2.5, CI = 1.0-6.1), and as coke oven workers (OR = 3.4; CI = 1.4-8.5). For stomach cancer, after adjusting for consumption of pickled vegetables, prior gastric diseases, family history of stomach cancer, low intake of fruits and vegetables, and education, risks were significantly elevated for those employed for 15 or more years in ore sintering and transportation (OR = 2.1, CI = 1.0-4.4), in the fire-resistant brick factory (OR = 2.5, CI = 1.1-5.8), in general loading (OR = 3.2, CI = 1.2-8.9), as boilerworkers and cooks (OR = 2.6, CI = 1.2-5.6), and as coke oven workers (OR = 5.4, CI = 1.8-16.0). For both lung and stomach cancers, significant dose-response gradients were observed for exposure to total dust and benzo(a)pyrene, but not for specific chemical components of dust. Overall, long-term steel workers with exposure to workplace pollutants had a 40% increased risk of both lung and stomach cancers. These case-control studies confirm many of the occupational findings reported in the proportionate mortality analysis, and suggest avenues for further work to evaluate the carcinogenicity of individual components of dust.

Analysis of polycyclic aromatic hydrocarbons in cooking oil fumes.

Various samples of cooking oil fumes were analyzed to an effort to study the relationship between the high incidence of pulmonary adenocarcinoma in Chinese women and cooking oil fumes in the kitchen. Polycyclic aromatic hydrocarbons (PAHs) in samples of cooking oil fumes were extracted, chromatographed, and measured by fluorescence spectrophotometer. The samples included oil fumes from three commercial cooking oils and fumes from three catering shops. All samples contained benzo(a)pyrene (BaP) and dibenzo (a,h)anthracene (DBahA). In addition, the concentration of DBahA was 5.7 to 22.8 times higher than that of BaP in the fume samples. Concentrations of BaP and DBahA were, respectively, 0.463 and 5.736 micrograms/g in refined vegetable oil, 0.341 and 3.725 micrograms/g in soybean oil, and 0.305 and 4.565 micrograms/g in vegetable oil. Investigation of PAH concentrations at three catering shops showed that the level of BaP at a Youtiao (deep-fried twisted dough sticks) shop was 4.18 micrograms/100 m3, 2.28 micrograms/100 m3 at a Seqenma (candied fritters) workshop, and 0.49 micrograms/100 m3 at a kitchen of a restaurant; concentrations of DBahA were 33.80, 14.41, and 3.03 micrograms/100 m3, respectively. The high concentration of carcinogens, such as BaP and DBahA, in cooking oil fumes might help explain why Chinese women, who spend more time exposed to cooking oil fumes than men, have a high incidence of pulmonary adenocarcinoma.

[Modifying effect of the chemical components of dust on the induction of lung tumors by physical and chemical carcinogens (experimental study]. / O modifitsiruiushchem vliianii khimicheskikh komponentov pyli na induktsiiu opukholei legkogo fizicheskim i khimicheskim kantserogenom (éksperimenta'lnoe issledovanie).

Chronic inhalation intake of benzo(a)pyrene (BP) and polonium-210 (210Po) together with aluminum oxide caused increase of tumor formation in the lungs of mice. Synergy of BP and 210Po carcinogenic effect was pointed out, it was characterized by summation and possible effect involution by tumor development rates and the duration of the latent period. BP and 210Po carcinogenic effectiveness depended on the type of dust carrier and probably on the presence of silicon dioxide and also carcinogenic metals. It was pointed out that further studies were necessary to determine an etiologic role of mineral dust chemical components in carcinogenic activity of the above substances and also carcinogenic effectiveness of dusts as carriers of chemical carcinogens and alpha-active radionuclides.