Multiple air pollutant exposure and lung cancer in Tehran, Iran.

Lung cancer is the most rapidly increasing malignancy worldwide with an estimated 2.1 million cancer cases in the latest, 2018 World Health Organization (WHO) report. The objective of this study was to investigate the association of air pollution and lung cancer, in Tehran, Iran. Residential area information of the latest registered lung cancer cases that were diagnosed between 2014 and 2016 (N = 1,850) were inquired from the population-based cancer registry of Tehran. Long-term average exposure to PM10, SO2, NO, NO2, NOX, benzene, toluene, ethylbenzene, m-xylene, p-xylene, o-xylene (BTEX), and BTEX in 22 districts of Tehran were estimated using land use regression models. Latent profile analysis (LPA) was used to generate multi-pollutant exposure profiles. Negative binomial regression analysis was used to examine the association between air pollutants and lung cancer incidence. The districts with higher concentrations for all pollutants were mostly in downtown and around the railway station. Districts with a higher concentration for NOx (IRR = 1.05, for each 10 unit increase in air pollutant), benzene (IRR = 3.86), toluene (IRR = 1.50), ethylbenzene (IRR = 5.16), p-xylene (IRR = 9.41), o-xylene (IRR = 7.93), m-xylene (IRR = 2.63) and TBTEX (IRR = 1.21) were significantly associated with higher lung cancer incidence. Districts with a higher multiple air-pollution profile were also associated with more lung cancer incidence (IRR = 1.01). Our study shows a positive association between air pollution and lung cancer incidence. This association was stronger for, respectively, p-xylene, o-xylene, ethylbenzene, benzene, m-xylene and toluene.

[Analysis of the literature on acute aromatic amino or nitro-compounds poisoning].

OBJECTIVE: To review the clinical features of acute toxicity of aromatic amino and nitro compounds. METHODS: A total of 110 papers reporting 1240 cases of acute toxicity induced by aromatic amino and nitro compounds from 1979 to 2013 were collected from CNKI, VIP, and Wanfang database, and were analyzed in this study. RESULTS: Of all included cases, 939 were caused by occupational exposure, and 301 were caused by exposure in daily life. A total of 1044 cases were male, and 196 were female. Age ranged from 9 days to 75 years. There were 13 cases of contact reaction. The numbers of mild, moderate, and severe toxicities were 358, 348, and 139, respectively, and the other 382 cases were not graded for severity. The average incubation period was 4.50±5.71 h (M = 3 h). The average incubation period of aniline toxicity was significantly shorter than that of nitrobenzene toxicity. Methemoglobinemia was found in 1146 cases, while cases of poisonings with 5-nitro-o-toluidine, 2-methyl-4-nitroaniline, and 3-chloro-2-methyl aniline were not found to have methemoglobinemia. The detection rates of MHb and HzB were 83.73% (674/805) and 40.19% (129/321), respectively. Sixty-two (19.31%) out of 321 cases were complicated by intravascular hemolysis, 270 (30.93%) out of 873 cases suffered hepatic impairment, 50 (12.25%) out of 408 cases were accompanied by renal damage. Consciousness disorders were found in 66 cases, and chemical cystitis was found in 36 cases. Oral poisoning could immediately induce severe symptoms including cyanosis, unconsciousness, and hemolysis. In prognosis analysis, it was found that the cure rate was 98.71% (1224/1240), and 14 cases of death were caused by multiple organ dysfunction syndrome, renal failure, uncontrolled hemorrhagic shock, myocardial infarction, and sudden death. Two cases were left with neurological sequelae. CONCLUSION: The clinical manifestations of poisoning with aromatic amino and nitro compounds are methemoglobinemia, intravascular hemolysis, liver damage, and renal damage. Treatment with specific medicine methylene blue can produce ideal clinical prognosis, but severe poisoning may cause death from multiple organ failure.

Characteristics and health impacts of volatile organic compounds in photocopy centers.

This study investigates the indoor air quality of typical photocopy centers in Taiwan to evaluate the human health risk following inhalation exposure. Both personal and area samplings were conducted at seven photocopy centers in the Tainan area from July 2002 to March 2003, which covered both summer and winter seasons in Taiwan. The benzene, toluene, ethylbenzene, xylenes, and styrene (BTEXS) measurements indicated no difference between personal and area samplings (P>0.05) and found that air conditioning improves indoor air quality. The additive factor at each photocopy center was significantly below 1.0, based on the current BTEXS permissible exposure limits in Taiwan. However, the mean benzene and styrene levels in the current study were 138 and 18 times, respectively, higher than those in another study conducted in the United States. Comparison of mass ratios of BTEXS with those of several chamber studies revealed that the photocopier is not the only volatile organic compound (VOC) source in photocopy centers. The lifetime cancer and noncancer risks for workers exposed to VOCs were also assessed. Results show that all seven centers in this study had a lifetime cancer risk exceeding 1x10(-6) (ranging from 2.5x10(-3) to 8.5x10(-5)). Regarding noncancer risk, levels of toluene, ethylbenzene, xylenes, and styrene were below the reference levels in all photocopy centers; however, the hazard indices for all still exceeded 1.0 (range 26.2-1.8) because of the high level of benzene in the photocopy centers.

Ethyl benzene-induced ototoxicity in rats: a dose-dependent mid-frequency hearing loss.

Rats were exposed to ethyl benzene at 0, 300, 400 and 550 ppm for 8 hours/day for 5 consecutive days. Three to six weeks after the exposure, auditory function was tested by measuring compound action potentials (CAP) in the frequency range of 1-24 kHz and 2f1-f2 distortion product otoacoustic emissions (DPOAEs) in the frequency range of 4-22.6 kHz. In addition, outer hair cell (OHC) loss was quantified by histological examination. The lowest concentration ethyl benzene had no effect on any of the above measures. At 400 ppm, auditory thresholds were increased by 15 and 16 dB at 12 and 16 kHz, respectively, and at 550 ppm by 24, 31, and 22 dB at 8, 12, and 16 kHz, respectively. DPOAE amplitude growth with stimulus level was affected only after 550 ppm at 5.6, 8, and 11.3 kHz. OHC loss was found in two of the five examined locations in the cochlea. At 400 ppm, 25% OHC loss was found at the 11- and 21-kHz region. The highest concentration evoked 40% and 75% OHC loss at the 11- and 21-kHz location, respectively. Thus, the mid-frequency region of rats is affected after exposure to relatively low concentrations of ethyl benzene (400-550 ppm). These results indicate that ethyl benzene is one of the most potent ototoxic organic solvents known today.

Acute bone marrow toxicity and pancytopenia following exposure to lead chromate, xylene, and ethylbenzene in a degloving injury.

A case of unique acute bone marrow toxicity and pancytopenia following subcutaneous exposure to lead chromate, xylene, and ethylbenzene in a previously healthy patient is reported. The patient sustained an extensive degloving injury to his lower extremity. The wound was contaminated with traffic paint containing lead chromate pigment along with a large volume of xylene and ethylbenzene solvent. Consequences of the patient's clinical course and management of degloving injuries are discussed.

[Analysis of thinner components using the Curie-point pyrolyzer-gas chromatographic method in the tissues of a victim fatally poisoned].

A 43-year-old male was found dead in the trunk of his car which was filled with thinner vapor. Thinner components in the tissues were analyzed using a gas chromatograph equipped with Curie-point pyrolyzer (Py-GC), and a gas chromatograph-mass spectrometer. The Py-GC method was able to analyze with very small materials. It was simple and quick but not as sensitive as the head-space gas chromatographic method. Toluene, ethylbenzene and xylenes were detected in the tissues, and their presence was confirmed by gas chromatography-mass spectrometry. The concentrations of toluene, ethylbenzene and xylenes in blood and the brain were 56.8, 6.8 and 4.5 micrograms/ml; and 203, 43.5 and 33.9 micrograms/g, respectively. The cause of death was thus judged as be thinner poisoning.

[Study of hyperchromatism caused by benzene derivatives]. / Estudio de las hipercromías por derivados bencénicos.

We report two patients with vitiligo-like lesions caused by contact with compounds containing phenols and toluene. The clinical, histopathologic and ultrastructural findings are compared with vitiligo. Two mechanisms may be present: one from direct enzymatic or cytotoxic action on melanocytes and the other through immunologic reaction.

Studies on kidney function in subjects exposed to organic solvents. III. Excretion of cells in the urine.

The excretion of erythrocytes and leucocytes in the urine from 101 men professionally exposed to styrene or toluene or to a combination of xylene and toluene was compared with the cell excretion in the urine from 39 non-exposed controls. The men exposed to organic solvents excreted significantly more cells than the controls. The findings are in agreement with the present discussion regarding the role of organic solvents in glomerular disease.

[Concentration of serum iron and transferrin saturation with iron as indices of changes resulting from chronic exposure to chemicals in industry]. / Stezenie zelaza w surowicy i wysycenie transferyny zelazem jako wskaznik nieswoistych zmian wywolanych przewlekla ekspozycja na substancje chemiczne w przemysle.

An attempt was undertaken to use the following indices of systemic changes resulting from longlasting occupational exposure to some chemicals: -- ferrum concentration in blood serum, the level of latent capacity to bind ferrum, and the degree of transferrin saturation with ferrum. The examination involved 177 clinically healthy men, aged 18--60. The control group consisted of 40 healthy men, aged 22--60. In 30.5% of persons, deviations were found, which might be induced by disturbances in general immunity of the organism, whereas in 16,4% the deviations might indicate chronic systemic changes.