Personal exposure monitoring of fine and coarse particulate matter using exposure assessment models for elderly residents in Hong Kong.

This study investigated the determinants of personal exposures (PE) to coarse (PM2.5-10) and fine particulate matter (PM2.5) for elderly communities in Hong Kong. The mean PE PM2.5 and PM2.5-10 were 23.6 ± 10.8 and 13.5 ± 22.1 µg/m3, respectively during the sampling period. Approximately 76% of study subjects presented statistically significant differences between PE and ambient origin for PM2.5 compared to approximately 56% for PM2.5-10, possibly due to the coarse-size particles being more influenced by similar sources (road dust and construction dust emissions) compared to the PM2.5 particles. Individual PE to ambient (P/A) ratios for PM2.5 all exceeded unity (≥1), suggesting the dominant influences of non-ambient particles contributed towards total PE values. There were about 80% individual P/A ratios (≤1) for PM2.5-10, implying possible effective infiltration prevention of larger size particulate matter particles leading to dominant influences from the outdoor sources. The higher concentration of NO3- and SO42- in PM2.5-10 compared to PM2.5 suggests possible heterogeneous reactions of alkaline minerals leading to the formation of NO3- and SO42- in PM2.5-10 particles. The PE and ambient OC/EC ratios in PM2.5 (8.8 ± 3.3 and 10.4 ± 22.4, respectively) and in PM2.5-10 (6.0 ± 1.9 and 3.0 ± 1.1, respectively) suggest possible secondary formed OC from surrounding rural areas. Heterogeneous distributions (COD >0.2) between the PE and ambient concentrations were found for both the PM2.5 and PM2.5-10 samples. The calibration coefficient as the association between personal and surrogate exposure measure of PE to PM2.5 (0.84) was higher than PM2.5-10 (0.52). The findings further confirm that local sources were the dominant contributor to the coarse particles and these coefficients can potentially be used to estimate different PE to PM2.5 and PM2.5-10 conditions. A comprehensive understanding of the PE to determinants in coarse particles is essential to further reduce potential exposure misclassification.

Occurrence and Risk Assessment of Personal PM2.5-Bound Phthalates Exposure for Adults in Hong Kong.

We performed personal PM2.5 monitoring involving 56 adult residents in Hong Kong. Additionally, paired personal and residential indoor fine particle (PM2.5) samples were collected from 26 homes and from 3 fixed monitoring locations (i.e., outdoor samples). Six PM2.5-bound phthalate esters (PAEs)-including dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DnBP), butyl benzyl phthalate (BBP), di(2-ethylhexyl) phthalate (DEHP), and di-n-octyl phthalate (DnOP)-were measured using a thermal desorption-gas chromatography/mass spectrometer method. Average ∑6PAEs (i.e., summation of six PAE congeners) concentrations in personal PM2.5 exposure (699.4 ng/m3) were comparable with those in residential indoors (646.9 ng/m3), and both were slightly lower than the outdoor levels. DEHP was the most abundant PAE congener (80.3%-85.0%) and found at the highest levels in different exposure categories, followed by BBP, DnBP, and DnOP. Strong correlations were observed between DEHP with DnBP (rs: 0.81-0.90; p < 0.01), BBP (rs: 0.81-0.90; p < 0.01), and DnOP (rs: 0.87-0.93; p < 0.01) in each exposure category. However, no apparent intercorrelations were shown for PAE congeners. Higher indoor concentrations and a stronger correlation between DMP and DEP were found compared with outdoor concentrations. Principal component analysis affirmed heterogeneous distribution and notable variations in PAE sources across different exposure categories. The average daily intakes of ∑6PAEs and DEHP via inhalation were 0.14-0.17 and 0.12-0.16 µg/kg-day for adults in Hong Kong. A time-weighted model was used to estimate PAE exposures incorporating residential indoor and outdoor exposure and time activities. The inhalation cancer risks attributable to measured and estimated personal exposure to DEHP exceeded the U.S. EPA's benchmark (1 × 10-6). The results provide critical information for mitigation strategies, suggesting that PAEs from both ambient and indoor sources should be considered when exploring the inhalation health risks of PAEs exposure.

Characterization and health risk assessment of airborne pollutants in commercial restaurants in northwestern China: Under a low ventilation condition in wintertime.

Impacts on indoor air quality of dining areas from cooking activities were investigated in eight categories of commercial restaurants including Szechwan Hotpot, Hunan, Shaanxi Noodle, Chinese Barbecue, Chinese Vegetarian, Korean Barbecue, Italian, and Indian, in Northwestern China during December 2011 to January 2012. Chemical characterization and health risk assessment for airborne carbonyls, and particulate-bound polycyclic aromatic hydrocarbons (PAHs) and heavy metals were conducted under low ventilation conditions in wintertime. The highest total quantified carbonyls (Σcarbonyls) concentration of 313.6µgm-3 was found in the Chinese Barbecue, followed by the Szechwan Hotpot (222.6µgm-3) and Indian (221.9µgm-3) restaurants. However, the highest Σcarbonyls per capita was found at the Indian restaurant (4500µgcapita-1), suggesting that cooking methods such as stir-fly and bake for spices ingredients released more carbonyls from thermal cooking processes. Formaldehyde, acetaldehyde, and acetone were the three most abundant species, totally accounting for >60% of mass concentrations of the Σcarbonyls. Phenanthrene, chrysene, and benzo[a]anthracene were the three most abundant PAHs. Low molecular weight fraction (ΣPAHs≤178) had the highest contributions accounting for 40.6%-65.7%, much greater than their heaver counterparts. Diagnostic PAHs ratios suggest that cooking fuel and environmental tobacco smoke (ETS) contribute to the indoor PAHs profiles. Lead was the most abundant heavy metal in all sampled restaurants. High quantity of nickel was also found in samples due to the emissions from stainless-steel made kitchen utensils and cookware and ETS. Cancer risk assessments on the toxic substances demonstrate that the working environment of dining areas were hazard to health. Formation of reactive organic species (ROS) from the cooking activities was evidenced by measurement of hydroxyl radical (OH) formed from simulating particulate matter (PM) react with surrogate lung fluid. The highest OH concentration of 294.4ngm-3 was detected in Chinese Barbecue. In addition, the elevation of the concentrations of PM and OH after non-dining periods implies that the significance of formation of oxidizing-active species indoor at poor ventilation environments.

Incidence and mortality of lung cancer: global trends and association with socioeconomic status.

We examined the correlation between lung cancer incidence/mortality and country-specific socioeconomic development, and evaluated its most recent global trends. We retrieved its age-standardized incidence rates from the GLOBOCAN database, and temporal patterns were assessed from global databases. We employed simple linear regression analysis to evaluate their correlations with Human Development Index (HDI) and Gross Domestic Product (GDP) per capita. The average annual percent changes (AAPC) of the trends were evaluated from join-point regression analysis. Country-specific HDI was strongly correlated with age-standardized incidence (r = 0.70) and mortality (r = 0.67), and to a lesser extent GDP (r = 0.24 to 0.55). Among men, 22 and 30 (out of 38 and 36) countries showed declining incidence and mortality trends, respectively; whilst among women, 19 and 16 countries showed increasing incidence and mortality trends, respectively. Among men, the AAPCs ranged from -2.8 to -0.6 (incidence) and -3.6 to -1.1 (mortality) in countries with declining trend, whereas among women the AAPC range was 0.4 to 8.9 (incidence) and 1 to 4.4 (mortality) in countries with increasing trend. Among women, Brazil, Spain and Cyprus had the greatest incidence increase, and all countries in Western, Southern and Eastern Europe reported increasing mortality. These findings highlighted the need for targeted preventive measures.

Characterization and health risk assessment of PM2.5-bound organics inside and outside of Chinese smoking lounges.

PM2.5 samples were collected at six indoor public places that contained dedicated smoking lounges. Samples were taken in the smoking lounges, at two indoor locations outside of the lounges, and in outdoor air near the venues. Organic carbon (OC), elemental carbon (EC), and non-polar organic compounds including polycyclic aromatic hydrocarbons (PAHs), n-alkanes (n-C16 to n-C40), iso/anteiso-alkanes (C29 to C33), hopanes and phthalate esters (PAEs) were quantified. Average PM2.5 levels of 170.2 ± 85.9 µg/m3 in the lounges exceeded limits of 25 µg/m3 set by World Health Organization (WHO); these levels were 5.4 and 3.9 times higher than those indoors and outdoors, respectively. High ratios of OC to PM2.5, OC to EC, and PAHs diagnostic ratios in the lounges indicated contributions from environmental tobacco smoke (ETS). The maximum carbon number (Cmax) and carbon preference indices (CPI) for n-alkanes showed ETS transport from the enclosed lounges to nearby indoor non-smoking areas. Iso/anteiso-alkanes in the lounges were 876.5 ng/m3, ∼80 times higher than outdoor levels. 17α(H)-21ß(H),30-norhopane and 17α(H)-21ß(H),(22R)-homohopane were much higher in the lounges than outdoor air, but they cannot be directly attributed to ETS. Estimated carcinogenic risks of PAHs in the lounges exceeded the acceptable level of 10- 6.

Microscale spatial distribution and health assessment of PM2.5-bound polycyclic aromatic hydrocarbons (PAHs) at nine communities in Xi'an, China.

Spatial variability of polycyclic aromatic hydrocarbons (PAHs) associated with fine particulate matter (PM2.5) was investigated in Xi'an, China, in summer of 2013. Sixteen priority PAHs were quantified in 24-h integrated air samples collected simultaneously at nine urban and suburban communities. The total quantified PAHs mass concentrations ranged from 32.4 to 104.7 ng m-3, with an average value of 57.1 ± 23.0 ng m-3. PAHs were observed higher concentrations at suburban communities (average: 86.3 ng m-3) than at urban ones (average: 48.8 ng m-3) due to a better enforcement of the pollution control policies at the urban scale, and meanwhile the disorganized management of motor vehicles and massive building constructions in the suburbs. Elevated PAH levels were observed in the industrialized regions (west and northwest of Xi'an) from Kriging interpolation analysis. Satellite-based visual interpretations of land use were also applied for the supporting the spatial distribution of PAHs among the communities. The average benzo[a]pyrene-equivalent toxicity (Σ[BaP]eq) at the nine communities was 6.9 ± 2.2 ng m-3 during the sampling period, showing a generally similar spatial distribution to PAHs levels. On average, the excess inhalation lifetime cancer risk derived from Σ[BaP]eq indicated that eight persons per million of community residents would develop cancer due to PM2.5-bound PAHs exposure in Xi'an. The great in-city spatial variability of PAHs confirmed the importance of multiple points sampling to conduct exposure health risk assessment.