Ching-Huang Lai

Sneezing and Allergic Dermatitis were Increased in Engineered Nanomaterial Handling Workers

The aim of this study was to survey the work-relatedness of symptoms and diseases among engineered nanomaterials handling workers by questionnaire. A total of 258 exposed workers and 200 comparison workers were recruited from 14 nanomaterials handling factories in Taiwan. In addition to current disease status (prevalence), we classified the diseases worsened by employment (worsened by work). The control banding nanotool risk level matrix was adopted to categorize the severity and probability of nanomaterial exposure. The work-relatedness of symptoms was also self-reported in the questionnaire. The only symptom identified as significantly work-related was sneezing (5.88% in risk level 2 and 7.91% in risk level 1 vs. 2.00% in controls, p=0.04). The prevalences of work-related dry cough (p=0.06) and productive cough (p=0.09) in nanomaterials handling workers were also higher than those in controls. The only disease significantly worsened by work was allergic dermatitis (4.20% in risk level 2, 0% in risk level 1 vs. 0.50% in control, p=0.01). The incidence of angina in nanoworkers was also higher than in controls (p=0.06). In addition to allergic diseases, cardiopulmonary symptoms such as cough and angina may be used as screening tools for medical surveillance of people handling engineered nanomaterials.

Elemental and organic carbon exposure in highway tollbooths: a study of Taiwanese toll station workers.

The carbon composition of fine particles (PM(2.5)) from traffic exhausts may play a role in adverse health effects. The objective of this study was to assess the concentrations of elemental and organic carbon in PM(2.5) in traffic exhausts from different types of vehicles in the booths of Taiwanese toll station workers and estimate the relations between traffic density and carbon concentrations. Tollbooth indoor monitoring samples were collected for 10 days to assess the 8 h integrated PM(2.5) concentration. Particle samples were analyzed for the content of total carbon, and elemental, and organic carbon. The mean carbon concentrations in the bus and truck lanes were [total: 167.7 microg/m(3) (SD 79.8 microg/m(3)); elemental: 131.7 (66.2); organic: 36.0 (25.8)], substantially higher compared with the car lanes with cash payment [39.2 (29.5); 20.2 (19.5); 19.2 (14.6)] and the car lanes with ticket payment [34.1 (26.1); 15.8 (17.6); 18.5 (12.2)]. The increase in elemental carbon concentration per vehicle in the bus and truck lane was 14 and 9 times greater than that of car lanes of ticket payment and car lanes of cash payment. The mass fraction of carbonaceous species in PM(2.5) accounted for 54% in bus and truck lanes, whereas the corresponding figure was 30-31% for car lanes. Elemental carbon is an important component of diesel exhaust. Workers in toll stations are exposed to high levels of both elemental and organic carbon.

Carbon monoxide: An old poison with a new way of poisoning

We present two events of carbon monoxide (CO) poisoning, which spread out through ventilation pipes to kill or injure neighbors. This is a previously undocumented poisoning process. Inxa0the first event, three people died and eight others suffered CO poisoning from a gas-powered water heater in an apartment building. Similar to the first event, three people expired and three others were injured by CO poisoning in the second event. We subsequently determined the cause of these tragedies were due to obstructions at the openings of ventilation pipes. COxa0is one of the most common causes of poisoning worldwide and these cases often result in tragedy. Early recognition of CO poisoning resulting from obstructed ventilation pipes will facilitate proper management and prevent possible lethal disasters. Additionally, all clinicians and other paramedical personnel ought to raise the suspicion of chemical-related casualties when encountering clusters of patients from a single locale.

An engineering intervention resulting in improvement in lung function and change in urinary 8-hydroxydeoxyguanosine among foundry workers in Taiwan

PurposeTo assess changes in oxidative DNA damage and lung function amongst a group of foundry workers resulting from an engineering intervention to reduce air respirable dust in their working environment.MethodsWe studied all 22 workers recruited from a typical small Taiwanese iron foundry plant before and 3xa0months after improvements to air exhaust control. The effectiveness of the air exhaust intervention in reducing respirable dust and SiO2 was determined by personal breathing-zone air sampling. Initial baseline biomarker measurements were taken of lung function and urinary 8-hydroxy-deoxyguanosine (8-OHdG) in all of the workers, with follow-up measurements taken 3xa0months after the engineering control was put in place. Generalized estimating equations were used to assess the effect of the intervention on lung function and oxidative DNA damage.ResultsFollowing the intervention, respirable dust density decreased from 2.87xa0±xa01.38xa0mg/m3 to 1.60xa0±xa00.70xa0mg/m3 (pxa0=xa00.07), and SiO2 concentration decreased from 0.43xa0±xa00.25xa0mg/m3 to 0.18xa0±xa00.11xa0mg/m3 (pxa0<xa00.05). Compared to initial baseline, significant improvements were found in lung function (FVC, FEV1, FVC%pred and FEV1%pred) amongst the workers after the engineering intervention. A significant increase in concentration of urinary 8-OHdG was observed after the engineering intervention in smokers, but not in non-smokers.ConclusionsThese findings indicate that reductions in workplace respirable dust and SiO2 concentration can result in improved lung function amongst foundry workers.

Exposure to fine particulate matter causes oxidative and methylated DNA damage in young adults: A longitudinal study

An increased understanding is needed of the physiological effects and plausible biological mechanisms that link PM2.5 (particulate matter with an aerodynamic diameter below 2.5μm) exposure to mortality and morbidities such as atherosclerosis and respiratory disease. PM2.5 causes carcinogenic health effects. Biomonitoring in humans has suggested that 8-oxo-7, 8-dihydro-2-deoxyguanosine (8-oxodG) and N7-methylguanine (N7-MeG) are correlated with oxidative and methylated DNA damage. Thus, it is meaningful to explore the mechanisms of mutagenesis and carcinogenesis associated with oxidative and methylated DNA damage by simultaneously measuring these two markers. We recruited 72 participants from 2 areas (residential and commercial as well as residential and industrial) in the greater Taipei metropolitan area at baseline. Personal samplers were used to collect 24-hour PM2.5-integrated samples. All participants completed an interview, and blood and urine samples were collected the next morning. All collection procedures were repeated twice after a two-month follow-up period. Urinary 8-oxodG and N7-MeG were assayed as biomarkers of oxidative and methylated DNA damage, respectively. Plasma superoxide dismutase (SOD) and glutathione peroxidase-1 (GPX-1) were measured as biomarkers of antioxidants. Urinary 1-hydroxypyrene (1-OHP) was used as a biomarker of exposure to polycyclic aromatic hydrocarbons (PAHs). The mean PM2.5 level was 37.3μg/m3 at baseline. PM2.5 concentrations were higher during winter than during spring and summer. After adjusting for confounds through a generalized estimating equation (GEE) analysis, N7-MeG was significantly increased by 8.1% (β=0.034, 95% CIs=0.001-0.068) per 10μg/m3 increment in PM2.5. 8-oxodG levels were positively correlated with N7-MeG according to both cross-sectional and longitudinal analyses, and 1-OHP was significantly associated with increasing 8-oxodG and N7-MeG concentrations. Exposure to PM2.5 increases methylated DNA damage. The mean level of urinary N7-MeG was 1000-fold higher than that of 8-oxodG.