Based on our studies for more than 20 years, we review the recent advances in sulfur dioxide (SO2) biology. Three sections are involved: (1) The studies on SO2 toxicological effects and its underlying mechanisms; (2) The new investigations on SO2 donor and physiological role of SO2 as a new type-gas transmitter; (3) The observations on pathophysiologic roles of SO2.
Animals ; Humans ; Physiological Phenomena ; Sulfur Dioxide ; metabolism ; toxicity

Air pollution in China comes from multiple sources, including coal consumption, construction and industrial dust, and vehicle exhaust. Coal consumption in particular directly determines the emissions of three major air pollutants: dust, sulfur dioxide (SO(2)), and nitrogen oxide (NOx). The rapidly increasing number of civilian vehicles is expected to bring NOx emission to a very high level. Contrary to expectations, however, existing data show that the concentrations of major pollutants [particulate matter-10 (PM10), SO(2), and nitrogen dioxide (NO(2))] in several large Chinese cities have declined during the past decades, though they still exceed the national standards of ambient air quality. Archived data from China does not fully support that the concentrations of pollutants directly depend on local emissions, but this is likely due to inaccurate measurement of pollutants. Analyses on the cancer registry data show that cancer burden related to air pollution is on the rise in China and will likely increase further, but there is a lack of data to accurately predict the cancer burden. Past experience from other countries has sounded alarm of the link between air pollution and cancer. The quantitative association requires dedicated research as well as establishment of needed monitoring infrastructures and cancer registries. The air pollution-cancer link is a serious public health issue that needs urgent investigation.
Air Pollutants ; toxicity ; Air Pollution ; adverse effects ; Carcinogens, Environmental ; toxicity ; China ; Coal ; Humans ; Neoplasms ; etiology ; Nitrogen Dioxide ; toxicity ; Particulate Matter ; toxicity ; Sulfur Dioxide ; toxicity ; Vehicle Emissions ; toxicity

Lactic dehydrogenase (LDH) isozyme pattens were examined in rats after exposing the animal to 250 ppm of sulfur dioxide gas. The isozymes of the respective tissues were separated on cellulose-acetate strips from the brain, lung, heart, liver, kidneys, and muscle, and visualized as the isozyme bands by the formazan reaction and analyzed by densitometry. As well as the above experiment, room-air and room-air+SO2 were aerated through tissue homoenates in-vitro, accompanied by pure oxygen aeration in order to see the in vitro effect of the gases on the LDH activity in the tissues mentioned with the following conclusions. (1) The H-type of LDH activity dominated in the normal heart tissue of rats, M-type in the normal lung, liver, and muscle tissues of the animal. (2) The kidney tissue of normal rats exhibited preponderance of LDH-1 and-5 isozymes, brain tissue in LDH-1 and-4 isozymes. (3) When rats inhaled sulfur dioxide gas in the concentration of 250 ppm, it appeared that the M-type tended to predominate in the anaerobic tissues and the H-type in the aerobic tissue. (4) The degree of oxygen tension seemed to be correlated with the low level of LDH activity in the anaerobic tissues such as liver and muscle and with the increased activity in the aerobic tissues, such as heart and lung. (5) The low oxygen tension seems to favor syn-thesis of M-type LDH and high oxygen tesnion H-type LDH in the tissues of rats.
Air Pollution ; Animal ; Citric Acid Cycle ; Densitometry ; Electrophoresis ; Environmental Exposure ; Isoenzymes ; Lactate Dehydrogenase/metabolism* ; Oxygen/metabolism ; Rats ; Sulfur Dioxide/toxicity* ; Substances: ; Isoenzymes ; Sulfur Dioxide ; Oxygen ; Lactate Dehydrogenase

OBJECTIVETo investigate the inhalation of sulfur dioxide (SO(2)) on the DNA damage of brain cells in mammalian animals.

METHODSingle cell microgel electrophoresis technique (comet test) was used to test the DNA damage of brain cells.

RESULTS(1) After the exposure to SO(2) at 0, 7, 14, 28 mg/m(3), the tail lengths of nuclear DNA in brain cells from male mice were 8.02, 23.14, 46.43 and 53.49 micro m respectively; and that from female mice were 7.23, 12.43, 20.39 and 54.83 micro m respectively. The results showed that: (1) SO(2) inhalation caused damage on DNA of brain cells in a dose-dependent manner; (2) Even under lower concentration of SO(2) as 7 mg SO(2)/m(3), the damage on DNA of brain cells was also reached to 98.8%. It implied that the brain cells of mammalian animals were very sensitive to SO(2) inhalation; (3) The DNA damage of brain cells from male mice is more serious than that from female mice. The reasons remain to be further studied.

CONCLUSIONSSO(2) pollution even at lower concentrations also had a potential risk to the genetic material DNA of brain cells from mammalian animals. The results of our study might explain the recently published epidemiological studies that the workers exposed to SO(2) or SO(2) derivatives had suffered an increase of mortality from brain cancer.

Administration, Inhalation ; Animals ; Brain ; drug effects ; metabolism ; DNA ; DNA Damage ; Dose-Response Relationship, Drug ; Female ; Male ; Mice ; Sulfur Dioxide ; toxicity

Air Pollutants ; toxicity ; Animals ; Female ; Lung ; drug effects ; pathology ; Male ; Nitrogen Dioxide ; toxicity ; Particulate Matter ; toxicity ; Pulmonary Surfactant-Associated Proteins ; metabolism ; Rats ; Rats, Wistar ; Sulfur Dioxide ; toxicity ; Uteroglobin ; metabolism

BackgroundAsthma is a common chronic respiratory disease and is related to air pollution exposure. However, only a few studies have concentrated on the association between air pollution and adult asthma. Moreover, the results of these studies are controversial. Therefore, the present study aimed to analyze the influence of various pollutants on hospitalization due to asthma in adults.

MethodsA total of 1019 unrelated hospitalized adult asthma patients from Northeast China were recruited from 2014 to 2016. Daily average concentrations of air pollutants (particulate matter <2.5 μm [PM], particulate matter <10 μm [PM], sulfur dioxide [SO], nitrogen dioxide [NO], and carbon monoxide [CO]) were obtained from the China National Environmental Monitoring Centre website from 2014 to 2016. Cox logistic regression analysis was used to analyze the relationship between air pollutants and hospital admissions in adult asthma.

ResultsThe maximum odds ratio (OR) value for most air pollutants occurred on lag day 1. Lag day 1 was chosen as the exposure period, and 8 days before onset was chosen as the control period. Three pollutants (PM, CO, and SO) were entered into the regression equation, and the corresponding OR (95% confidence interval) was 0.995 (0.991-0.999), 3.107 (1.607-6.010), and 0.979 (0.968-0.990), respectively.

ConclusionsA positive association between hospital admissions and the daily average concentration of CO was observed. CO is likely to be a risk factor for hospital admissions in adults with asthma.

Air Pollutants ; toxicity ; Air Pollution ; adverse effects ; Asthma ; epidemiology ; Carbon Monoxide ; toxicity ; China ; Environmental Monitoring ; statistics & numerical data ; Female ; Hospitalization ; statistics & numerical data ; Humans ; Male ; Odds Ratio ; Particulate Matter ; toxicity ; Risk Factors ; Sulfur Dioxide ; toxicity

OBJECTIVETo investigate effects of short-term sulfur dioxide inhalation to the liver.

METHODSHaematoxylin and eosin staining (HE) and transmission electron microscopy (TEM) were used to study the pathologic changes in mice liver after sulfur dioxide (SO(2)) inhalation.

RESULTSExposure to 56 mg/m(3), 112 mg/m(3) 168 mg/m(3) SO(2) caused increasingly severe liver injuries, as detected by HE staining and TEM. The morphologic changes included spotty necrosis with lymphocyte, monocyte, and neutrophil infiltration, fatty degeneration of hepatocytes with dilatation of rough endoplasmic reticulum and dissociation of ribosomes, as well as degeneration of mitochondria and karyorrhexis.

CONCLUSIONSO(2) inhalation can cause marked liver injury in experimental settings.

Administration, Inhalation ; Animals ; Hepatocytes ; drug effects ; pathology ; Liver ; drug effects ; pathology ; ultrastructure ; Male ; Mice ; Microscopy, Electron ; Sulfur Dioxide ; administration & dosage ; toxicity

OBJECTIVES: The association between concentrations of sulfur dioxide (SO), nitrogen dioxide (NO), carbon monoxide (CO), ozone (O), and emergency ambulance dispatches (EADs) for asthma was explored in the central Sichuan Basin of southwestern China for the first time. METHODS: EADs for asthma were collected from the Chengdu First-Aid Command Center. Pollutant concentrations were collected from 24 municipal environmental monitoring centers and including SO, NO, CO, daily 8-h mean concentrations of O (O-8 h), and particulate matter less than 2.5 μm in aerodynamic diameter (PM). The climatic data were collected from the Chengdu Municipal Meteorological Bureau. All data were collected from years spanning 2013-2017. A time-stratified case-crossover design was used to analyze the data. RESULTS: After controlling for temperature, relative humidity, and atmospheric pressure, IQR increases in SO (13 μg/m), NO (17 μg/m), and CO (498 μg/m) were associated with 18.8%, 11.5%, and 3.1% increases in EADs for asthma, respectively. The associations were strongest for EADs and SO, NO, and CO levels with 3-, 5-, and 1-day lags, respectively. CONCLUSIONS This study provides additional data to the limited body of literature for potential health risks arising from ambient gaseous pollutants. The results of the study suggest that increased concentrations of SO, NO, and CO were positively associated with emergency ambulance dispatches for asthma in Chengdu, China. Further studies are needed to investigate the effects of individual air pollutants on asthma.
Air Pollutants ; analysis ; toxicity ; Asthma ; chemically induced ; epidemiology ; Carbon Monoxide ; analysis ; toxicity ; China ; epidemiology ; Cities ; Cross-Over Studies ; Emergency Medical Dispatch ; statistics & numerical data ; Environmental Monitoring ; statistics & numerical data ; Humans ; Nitrogen Dioxide ; analysis ; toxicity ; Ozone ; analysis ; toxicity ; Particle Size ; Particulate Matter ; analysis ; toxicity ; Risk ; Sulfur Dioxide ; analysis ; toxicity

OBJECTIVES: The deleterious effects of air pollution on various health outcomes have been demonstrated. However, few studies have examined the effects of air pollution on liver enzyme levels. METHODS: Blood samples were drawn up to three times between 2008 and 2010 from 545 elderly individuals who regularly visited a community welfare center in Seoul, Korea. Data regarding ambient air pollutants (particulate matter < or =2.5 mum [PM2.5], nitrogen dioxide [NO2], ozone [O3], carbon monoxide, and sulfur dioxide) from monitoring stations were used to estimate air pollution exposure. The effects of the air pollutants on the concentrations of three liver enzymes (aspartate aminotransferase [AST], alanine aminotransferase [ALT], and gamma-glutamyltranspeptidase [gamma-GTP)]) were evaluated using generalized additive and linear mixed models. RESULTS: Interquartile range increases in the concentrations of the pollutants showed significant associations of PM2.5 with AST (3.0% increase, p=0.0052), ALT (3.2% increase, p=0.0313), and gamma-GTP (5.0% increase, p=0.0051) levels; NO2 with AST (3.5% increase, p=0.0060) and ALT (3.8% increase, p=0.0179) levels; and O3 with gamma-GTP (5.3% increase, p=0.0324) levels. Significant modification of these effects by exercise and alcohol consumption was found (p for interaction <0.05). The effects of air pollutants were greater in non-exercisers and heavy drinkers. CONCLUSIONS: Short-term exposure to air pollutants such as PM2.5, NO2, and O3 is associated with increased liver enzyme levels in the elderly. These adverse effects can be reduced by exercising regularly and abstinence from alcohol.
Aged ; Aged, 80 and over ; Air Pollutants/analysis/*toxicity ; Alanine Transaminase/blood ; *Alcohol Drinking ; Aspartate Aminotransferases/blood ; Environmental Exposure ; *Exercise ; Female ; Humans ; Linear Models ; Liver/*drug effects/enzymology ; Male ; Nitrogen Dioxide/chemistry/toxicity ; Ozone/chemistry/toxicity ; Particulate Matter/analysis/toxicity ; Sulfur Dioxide/chemistry/toxicity ; gamma-Glutamyltransferase/blood

OBJECTIVETo study the relationship between ambient air pollution and daily mortality of SARS in Beijing.

METHODSThe approach of time-series Poisson regression was used to assess the relationship between daily SARS mortality, ambient air pollution, and other factors from April 25 to May 31, 2003 in Beijing.

RESULTSAn increase of each 10 microg/m3 over a 5-day moving average of PM10, SO2 and NO2 corresponded to 1.06 (1.00-1.12), 0.74 (0.48-1.13) and 1.22 (1.01-1.48) relative risks (RRs) of daily SARS mortality, respectively. The relative risks (RRs) values depended largely on the selection of lag days.

CONCLUSIONThe daily mortality of SARS might be associated with certain air pollutants in Beijing.

Air Pollutants ; adverse effects ; analysis ; toxicity ; Air Pollution ; adverse effects ; analysis ; China ; epidemiology ; Cities ; Dust ; analysis ; Environmental Monitoring ; Epidemiological Monitoring ; Humans ; Nitrogen Dioxide ; analysis ; Particle Size ; Retrospective Studies ; Risk ; Severe Acute Respiratory Syndrome ; epidemiology ; mortality ; Sulfur Dioxide ; analysis