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1.
Sci Total Environ ; 715: 136992, 2020 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-32023515

RESUMO

When addressing particulate matter (PM) emissions from residential solid fuel combustion, ultrafine particles are usually merged into PM2.5, while whose mass concentration is applied as the index in evaluating PM pollution as well as assessing PM-induced health risk. This may not effectively represent the risk from ultrafine particles. In this study, we explored ultrafine particle emissions during residential combustion under both laboratory-controlled and real-world rural household conditions. Significant ultrafine particle emissions (i.e. with emission factors between 2 × 1015 to 2 × 1016 particles per kg of fuel) are found for both coal and biomass. High emissions of particle mass concentration often occur at the beginning of the combustion (i.e. the first 30 min after fire start) while high emissions of particle number concentration occur in a later combustion period (60-150 min). Ultrafine particles account for over 90% of the emitted total particle number concentration from 3 nm to 10 µm. These emissions elevate ultrafine particle number concentration by more than a decade in indoor environment under which household residents are directly exposed. In addition, we show that there is notable inconsistency between reducing PM2.5 mass based emissions and reducing ultrafine particle number based emissions among various control strategies that were proposed for reducing pollution from residential combustion. Both "cleaner" fuels and stoves that are designed to reduce PM2.5 emissions are found to be not necessarily effective in reducing ultrafine particle emissions, even increase their emissions in some cases. These findings indicate that the overlook of ultrafine particle emissions from residential solid fuel combustion can lead to potential health risk to household residents, especially to those vulnerable ones (e.g., the elderly and children) who are more sensitive to indoor air pollution. More attentions are needed on ultrafine particle pollution and its potential health risk in comparison to using the PM mass concentration index alone.

2.
Mol Med Rep ; 21(3): 1304-1309, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31922232

RESUMO

Long noncoding (lnc)RNA HAND2­AS1 inhibits the development of several human malignancies. The role of HAND2­AS1 was investigated in hepatocellular carcinoma (HCC). It was found that levels of HAND2­AS1 in serum were significantly lower, while serum levels of Rho­associated protein kinase 2 (ROCK2) in HCC patients were significantly increased compared with hepatitis B (HB) patients and healthy controls. Decreased HAND2­AS1 levels distinguished HCC patients but not HB patients from healthy controls. A significant negative correlation between HAND2­AS1 and ROCK2 was found in HCC patients but not in HB patients or healthy controls. HAND2­AS1 overexpression inhibited, while ROCK2 overexpression promoted HCC cell migration, proliferation and invasion. HAND2­AS1 overexpression led to downregulated ROCK2 expression. ROCK2 overexpression did not significantly affect ROCK2 expression but attenuated the inhibitory effects of HAND2­AS1 overexpression. It was therefore concluded that HAND2­AS1 might mediate the downregulation of ROCK2 in HCC to inhibit cancer cell migration, proliferation and invasion.

3.
Environ Pollut ; 258: 113728, 2019 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-31877468

RESUMO

The emission and deposition of global atmospheric phosphorus (P) have long been considered unbalanced, and primary biogenic aerosol particles (PBAP) and phosphine (PH3) are considered to be the only atmospheric P sources from the ecosystem. In this work, we found and quantified volatile organic phosphorus (VOP) emissions from plants unaccounted for in previous studies. In a greenhouse in which lemons were cultivated, the atmospheric total phosphorus (TP) concentration of particulate matter (PM) was 41.8% higher than that in a greenhouse containing only soil, and the proportion of organic phosphorus (OP) in TP was doubled. 31P nuclear magnetic resonance tests (31P-NMR) of PM showed that phosphate monoesters were the main components contributed by plants in both the greenhouse and at an outside observation site. Atmospheric gaseous P was directly measured to be 1-2 orders of magnitude lower than P in PM but appeared to double during plant growing seasons relative to other months. Bag-sampling and gas chromatography mass spectrometry (GCMS) tests showed that the gaseous P emitted by plants in the greenhouse was triethyl phosphate. VOP might be an important component of atmospheric P that has been underestimated in previous studies.

4.
Indoor Air ; 2019 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-31755597

RESUMO

Stunting adversely affects physical and mental outcomes of children. It has not been examined whether household air pollution from solid fuel combustion is a risk factor for stunting in children. In a total of 41,439 children aged 6-17 across China, height was measured using a unified protocol. Multivariable linear regression models and logistic regression models were used to assess the associations of solid fuel use for cooking/heating with stunting in children. Adjusted for covariates, cooking/heating with solid fuel was significantly associated with a lower z-score for height for age and sex (ß = -0.21 [-0.32 to -0.09] and -0.17 [-0.31 to -0.03], respectively) and an increased risk of stunting with an estimated ORs of 1.34 [1.07~1.68] and 1.37 [1.02~1.83], respectively. The risk of stunting associated with solid fuel use was statistically significant in high-age children. And the effect was greater on girls than on boys, though the difference was not statistically significant. Our study suggested that Chinese children living in households using solid fuel had a significantly higher risk of stunting than those living in households using cleaner fuel.

5.
Environ Int ; 133(Pt B): 105242, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31665677

RESUMO

Preterm birth (PTB) can give rise to significant neonatal morbidity and mortality, as well as children's long-term health defects. Many studies have illustrated the associations between ambient air pollution exposure during gestational periods and PTB risks, but most of them only focused on one single air pollutant, such as PM2.5. In this population-based environmental-epidemiology study, we recruited 6275 pregnant mothers in Zhejiang Province, China, and evaluated their gestational exposures to various air pollutants during 2013-2017. Time-to-event logistic regressions were performed to estimate risk associations after adjusting all confounders, and Quasi-AQI model and PCA-GLM analysis were applied to resolve the collinearity issues in multi-pollutant regression models. It was found that gestational exposure to ambient air pollutants was significantly associated with the occurrence of PTB, and SO2 was the largest contributor with a proportion of 29.4%. Three new variables, prime factor (a combination of PM2.5, PM10, SO2, and NO2), carbon factor (CO), and ozone factor (O3), were generated by PCA integration, contributing 63.4%, 17.1%, and 19.5% to PTB risks, respectively. The first and third trimester was the most crucial exposure window, suggesting the pregnant mothers better to avoid severe air pollution exposures during these sensitive periods.

6.
Environ Sci Technol ; 53(19): 11337-11344, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31486635

RESUMO

Historically, beehive coke ovens (BCOs) were extensively operated in China and emitted large quantities of pollutants, including primary PM2.5 and secondary PM2.5 precursors, and other climate forcers. Although these ovens were legally banned in 1996 by the Coal Law, the process of phasing them out took over a decade to accomplish. Based on historical operation data derived from remote sensing images, temporal trends and the spatial distribution of the emissions of various pollutants from BCOs were compiled and used to model the resulting perturbation in ambient PM2.5, population exposure, and PM2.5-associated adverse health impacts. Historically, PM2.5 originating from BCOs affected a vast region across China, which peaked in approximately 1996 and decreased afterward until the ovens' final elimination in 2011. According to the results of a supply-demand model, emissions from the BCOs would have continued to increase after 1996 if they had not been banned. As a result, national average PM2.5 attributable to BCOs in 2014 would have been more than three times as high as that in 1996. It was estimated that the cumulative number of premature deaths associated with BCO-originating PM2.5 from 1982 to 2014 was as high as 365 000 (95% confidence interval 259 000-402 000). The number would have nearly tripled if BCOs had not been banned and halved if the ban had been implemented immediately after the regulation was in force, suggesting the importance of legislation implementation.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Coque , China , Material Particulado
7.
Nat Commun ; 10(1): 3405, 2019 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-31363099

RESUMO

Rural residential energy consumption in China is experiencing a rapid transition towards clean energy, nevertheless, solid fuel combustion remains an important emission source. Here we quantitatively evaluate the contribution of rural residential emissions to PM2.5 (particulate matter with an aerodynamic diameter less than 2.5 µm) and the impacts on health and climate. The clean energy transitions result in remarkable reductions in the contributions to ambient PM2.5, avoiding 130,000 (90,000-160,000) premature deaths associated with PM2.5 exposure. The climate forcing associated with this sector declines from 0.057 ± 0.016 W/m2 in 1992 to 0.031 ± 0.008 W/m2 in 2012. Despite this, the large remaining quantities of solid fuels still contributed 14 ± 10 µg/m3 to population-weighted PM2.5 in 2012, which comprises 21 ± 14% of the overall population-weighted PM2.5 from all sources. Rural residential emissions affect not only rural but urban air quality, and the impacts are highly seasonal and location dependent.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar em Ambientes Fechados/análise , Fontes Geradoras de Energia , Poluição do Ar , Características da Família , Habitação/estatística & dados numéricos , Humanos , Material Particulado/análise , Saúde da População Rural/estatística & dados numéricos
8.
Environ Int ; 127: 550-557, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30981913

RESUMO

In the past two decades, neonicotinoid insecticides have been widely used in agricultural activities in China. Many previous studies have investigated the neonicotinoid pollution in aquatic ecosystems, but the status of water safety of neonicotinoid uses in China is very scarce. The present study aims to reveal the spatial and temporal distribution of neonicotinoids in rivers, and then evaluate the ecological risks to aquatic animals. Water samples were collected from all sixteen rivers along the east coast of China during the dry and wet seasons in 2016, and nine individual commercialized neonicotinoids were quantified. Higher concentrations were found during the dry season (343 ±â€¯210 ng/L) compared to those during the wet season (174 ±â€¯162 ng/L). The concentration of neonicotinoid insecticides in river water is mainly affected by the intensity of agricultural activities. The spatial and temporal pollution patterns we discovered suggested the use of neonicotinoids has shifted from old types (i.e., imidacloprid and acetamiprid) to new types (i.e., dinotefuran and nitenpyram) in some areas. The estimated annual quantity of neonicotinoids released into the adjacent seas totaled 1256 ±â€¯780 tons, most of which (95%) ran into the East China Sea due to heavy agricultural use in the Yangtze River Basin. Using the species sensitive distribution (SSD) method, the thresholds for aquatic animals were determined (acute: 362 ng/L; chronic: 58 ng/L). Under current agricultural practices, 27% and 84% of the river water samples exceeded the thresholds for acute and chronic ecological risks, suggesting intervention programs are in urgent need to ensure river water safety for aquatic life in China.


Assuntos
Ecossistema , Inseticidas/análise , Rios/química , Poluentes Químicos da Água/análise , China , Medição de Risco
9.
Environ Sci Technol ; 53(5): 2539-2548, 2019 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-30754969

RESUMO

Neonicotinoid insecticides have been widely consumed worldwide, particularly in China. There is a growing interest in the environmental research community about the occurrence, fates, sources, and risks of neonicotinoids. Nine neonicotinoids in river/lake water were measured at 12 sites along the Yangtze River Basin during the dry and wet seasons in 2016, and nonpoint sources were also identified based on a modified mass balance method. A significantly higher concentration of neonicotinoids was found during the dry season probably due to the dilution effect and insecticide consumption. The high pollution levels are due to posing high ecological risks compared with the recommended thresholds. In 2016, 1190 (95% confidence interval (CI) = 822-1690) tons of neonicotinoids were transferred into the adjacent sea. Nonpoint source pollution (1700 (CI = 1200-2370) tons) was the major contributor (91.3%) to the total input of neonicotinoids into the system. Composition profiles identifying specific neonicotinoid sources indicated some changes in usage patterns from old to new types of neonicotinoids. This spatial and seasonal field study and source identification is expected to fill the data gap regarding the limited information on neonicotinoid use patterns and to inform further effective policy-making and intervention programs in China that should be urgently promoted in the near future.


Assuntos
Poluição Difusa , Poluentes Químicos da Água , China , Monitoramento Ambiental , Neonicotinoides , Rios
10.
Environ Sci Technol ; 53(1): 521-529, 2019 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-30512946

RESUMO

Household energy use is an important aspect of environmental pollution and sustainable development. From a nationwide residential energy survey, this study revealed that household fuel "stacking"-mixed use of multiple fuels-is becoming noticeable over the 20 years from 1992 to 2012, particularly in northern China where space heating is needed in the winter. Approximately 28% of rural households used only one single energy type in 1992, whereas the percentage declined to merely 11% in 2012. The number of energy types correlated positively with the heating degree days and negatively with the household income in areas with limited or no heating requirements. Combined use of biomass and fossil fuels may lead to extra energy use, up to 40% for cooking and 20% for heating. Some fuels, as supplementary ones, are used more often than others, and the energy consumption of coal and honeycomb briquette could be underestimated by 34% and 22% if only the primary energy was accounted for. Generally, household energy is shifting from solid fuels to cleaner ones, such as electricity or gas for both cooking and heating, but with different patterns and transition rates. Transition pathways varied extensively from one region to another due to the imbalanced development. Clean transitions initially occur in well-developed provinces and megacities and then extend to inland provinces approximately 5-10 years later. Rapid energy transitions and urbanization have led to nearly 50% reduction in residential energy consumption over these two decades, consequently resulting in significant declines in emissions of most air pollutants. The updated residential emission of primary PM2.5 was 3100 Gg in 2014. Extensively fuel stacking and rapid energy transitions have led to complex circumstances in energy use.


Assuntos
Poluentes Atmosféricos , Poluição do Ar em Ambientes Fechados , China , Carvão Mineral , Culinária , Humanos , Material Particulado
11.
Sci Total Environ ; 656: 239-249, 2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30504024

RESUMO

Black carbon (BC) is important due to its complex influences on the environment and on climate in particular. However, reported BC data are largely dependent on measurement techniques due to the multitude of measurement principles. Here we focused on thermal-optical method which has been widely used to determine BC mass (as elemental carbon, EC). Several factors influencing EC measurement were investigated. Results from source samples representing vehicle engine emissions pointed to a continuum of EC components in thermal stability and provided direct observational evidence for the premature evolution of EC in inert atmosphere. It was also found that EC masses may be substantially underestimated for the vehicle exhaust samples if the adopted protocol requires an oxidizing atmosphere to define the split point between organic carbon (OC) and EC. Results from a field campaign conducted during winter in Beijing showed that the optical attenuation (ATN; i.e., the filter transmittance signal, I) was largely saturated for the samples with relatively high loadings, indicating their EC results were unreliable. Improved measurement of EC was achieved by extracting these heavily loaded filters using methanol, given that ATN was considerably reduced by the extraction and, moreover, saturation of ATN (or I) became not evident for the extracted samples. The methanol extraction also significantly reduced the transformation of OC to char-OC, by removing the majority (i.e., ~85%) of the deposited organic aerosols. Higher EC were measured for the extracted samples compared with the untreated ones, indicating that EC tends to be underestimated due to the charring-induced uncertainties. In addition, the methanol extraction largely reduced the inter-protocol discrepancy in the EC measurement results. Similar effects of methanol extraction have been observed during summer in Beijing, despite the seasonal variations of aerosol sources and compositions. This study indicates the potential benefits of methanol extraction for EC measurement.

12.
Environ Pollut ; 244: 304-313, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30343231

RESUMO

Indoor air contributes significantly to overall exposure, particularly for rural Chinese who often use solid fuels for cooking and/or heating. Unfortunately, overlooked rural indoor air leads to a critical knowledge gap. Simultaneous measurements in the kitchen, living room, and immediately outside of houses using six-channel particle counters were carried out in 18 biomass-burning rural and 3 non-biomass-burning urban households (as a comparison) in winter to characterize dynamic change patterns indoor air pollution and indoor-outdoor relationship. The rural households mainly used wood or crop residues for cooking and heating, while the urban households used pipelined natural gas for cooking and air conditioners for heating. In rural households with significant solid-fuel burning internal sources, the highest concentration was found in the kitchen (101 ±â€¯56 µg/m3), with comparable levels in the living room (99 ±â€¯46 µg/m3) and low levels in outdoor air (91 ±â€¯39 µg/m3). A generally opposite direction of indoor-outdoor exchange was found between the rural and urban households. PM in kitchen air is smaller than that in living rooms and outdoors because solid fuel burning (mainly in rural households) and cooking oil heating (in rural and urban households). Indoor and outdoor PM concentration changed synchronously, with a slight delay in indoor air in urban households but a slight delay in outdoor air in rural households. Cooking, heating, and smoking elevated indoor PM significantly, but different from the cooking activity that produced peaks lasting for about 30 min, emissions from heating created a series of peaks due to frequent disturbance and fuel-feeding and had more significant impacts on the daily average concentration. Distinct indoor-outdoor relationships and dynamic change patterns between the two household categories w/o strong internal biomass burning sources imply that totally different model schemes are needed to quantitatively address indoor air pollution and inhalation exposure.


Assuntos
Poluição do Ar em Ambientes Fechados/análise , Monitoramento Ambiental/métodos , Exposição por Inalação/análise , Material Particulado/análise , Biomassa , Culinária , Calefação , Humanos , População Rural , Estações do Ano , Madeira/química
13.
Sci Total Environ ; 647: 962-972, 2019 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-30180371

RESUMO

Emissions of polycyclic aromatic hydrocarbons (PAHs) in China remain at a high level compared to those in developed countries. The Yangtze River Delta (YRD) is an economic and industrial center in China with an extremely large population. The potentially high emissions and excess cancer risk from human exposure in this region cannot be neglected. This study applied a multimedia model to estimate the concentrations of 16 US EPA priority PAHs in the environment in the YRD with a well-developed PAH-emission inventory for 2014. The model predicted that the average concentrations of ΣPAHs were 274 ng/m3 in the air, 255 ng/g in the soil, 15 ng/g in vegetation, 147 ng/L in freshwater and 144 ng/g in sediment, as well as 99 ng/L and 80 ng/g in seawater and sediment, respectively. Soil is the PAH sink in this region, and the net flux of the total PAHs is always from air to soil for each isomer. A deterministic assessment observed that the ELCR (excess lifetime cancer risk) ranged from 2.5 × 10-6 to 3.0 × 10-5 for exposure by air inhalation and from 3.5 × 10-7 to 7.9 × 10-6 for exposure by soil ingestion. The probabilistic results did not find any probability of ELCR >10-4 by exposure via soil ingestion in the YRD. The probabilistic ELCR induced by inhalation exposure varied from 8.1 × 10-7 to 3.1 × 10-4 in the YRD. This study provided a comprehensive overview of PAHs occurrence in natural environments and of the relevant human health risks. The information presented in this study could help authorities to enact a strategy regarding emission reduction and pollution control relevant to PAHs. CAPSULE: Multimedia modeling predicted distributions and compositions of PAHs in different environmental compartments, and deterministic and probabilistic ELCRs induced by air inhalation and soil ingestion were also provided.


Assuntos
Exposição Ambiental/estatística & dados numéricos , Modelos Químicos , Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes Químicos da Água/análise , Poluição Química da Água/estatística & dados numéricos , China , Monitoramento Ambiental , Humanos , Multimídia , Medição de Risco , Rios
14.
Environ Sci Technol ; 52(21): 12886-12894, 2018 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-30290697

RESUMO

Survey data from a comprehensive national survey of ∼34 000 households were analyzed for the mix status and transition trajectory of energy for boiling water in rural Chinese households from 1992 to 2012. In 1992, ∼6% of households reported using electricity, biogas, or liquefied petroleum gas (LPG) to boil drinking water; in 2012, the proportion was ∼60%. Income per capita appeared most strongly associated with this transition toward electricity and other clean fuels. Median annual incomes for households using biomass fuels, electric kettles, and LPG were RMB 15 000, 28 000, and 30 000, respectively. Overall, the transition was most pronounced in eastern China, a region which experienced relatively higher rates of economic growth over the same 20-year period. Energy type preferences appear to be highly dependent on fuel accessibility such that coal and straw usage was higher in provinces with higher coal and grain production. These trends suggest that electric kettle use would likely increase from ∼29% (2012) to ∼60% by 2030, at which point <5% of rural households would be expected to boil with solid fuels. Recent evidence suggests that this transition could contribute to reductions in water-related gastrointestinal illness as well as reductions in air pollutant emissions in rural China.


Assuntos
Poluição do Ar em Ambientes Fechados , China , Carvão Mineral , Culinária , Estudos Transversais , Saúde Ambiental , Humanos
15.
Environ Sci Technol ; 52(18): 10416-10425, 2018 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-30118598

RESUMO

Although PM2.5 (particulate matter with aerodynamic diameters less than 2.5 µm) in the air originates from emissions, its concentrations are often affected by confounding meteorological effects. Therefore, direct comparisons of PM2.5 concentrations made across two periods, which are commonly used by environmental protection administrations to measure the effectiveness of mitigation efforts, can be misleading. Here, we developed a two-step method to distinguish the significance of emissions and meteorological factors and assess the effectiveness of emission mitigation efforts. We modeled ambient PM2.5 concentrations from 1980 to 2014 based on three conditional scenarios: realistic conditions, fixed emissions, and fixed meteorology. The differences found between the model outputs were analyzed to quantify the relative contributions of emissions and meteorological factors. Emission-related gridded PM2.5 concentrations excluding the meteorological effects were predicted using multivariate regression models, whereas meteorological confounding effects on PM2.5 fluctuations were characterized by probabilistic functions. When the regression models and probabilistic functions were combined, fluctuations in the PM2.5 concentrations induced by emissions and meteorological factors were quantified for all model grid cells and regions. The method was then applied to assess the historical and future trends of PM2.5 concentrations and potential fluctuations on global, national, and city scales. The proposed method may thus be used to assess the effectiveness of mitigation actions.


Assuntos
Poluentes Atmosféricos , Cidades , Monitoramento Ambiental , Conceitos Meteorológicos , Material Particulado
16.
Environ Pollut ; 242(Pt B): 1587-1597, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30097283

RESUMO

Residential combustion emission contributes significantly to ambient and indoor air pollution in China; however, this pollution source is poorly characterized and often overlooked in national pollution control policies. Few studies, and even fewer field-based investigations, have evaluated pollutant emissions from indoor biomass burning. One significant feature of Chinese household biofuel stoves is that many are built on site. In this study, 112 tests were conducted to investigate pollutant emission factors and variations for 11 fuel-stove combinations in actual use in the field. Results showed that, compared to those emission tests under controlled fuel burning conditions, EFs of methane, sulfur dioxide, particulate matter, and organic carbon from the field-based uncontrolled tests were higher, but carbon monoxide, nitrogen oxides, and elemental carbon were not significantly different. Controlled burning tests may be unrepresentative of real-world fuel burning. Pollutant emissions from uncontrolled burning tests had much higher variations compared with controlled tests. Most pollutant emissions from indoor straw burning are higher than that in open burning, except nitrogen oxides. The typical built-in-place home stoves in China had low efficiencies and high pollutant emissions that were rated as Tier 0 (the worst) or Tier 1 of a four-tier scale according to the International Organization for Standardization, International Workshop Agreement 11-2012. Effective interventions are expected to lower pollutant emissions from residential combustion to improve air quality and to protect human health.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar em Ambientes Fechados/análise , Poluição do Ar , Material Particulado/análise , Biomassa , Carbono/análise , Monóxido de Carbono/análise , China , Monitoramento Ambiental , Utensílios Domésticos , Óxidos de Nitrogênio/análise
17.
Environ Int ; 119: 117-124, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29957353

RESUMO

Exposure to and the related burden of diseases caused by pollution from solid fuel cooking, known as household air pollution (HAP), has been incorporated in the assessment of the Global Burden of Diseases (GBD) project. In contrast, HAP from space heating using solid fuels, prevalent in countries at middle or high altitudes, is less studied and missing from the GBD assessment. China is an ideal example to estimate the bias of exposure and burden of diseases assessment when space heating is neglected, considering its remarkably changing demands for heating from the north to the south and a large solid-fuel-dependent rural population. In this study, based on a meta-analysis of 27 field measurement studies in rural China, we derive the indoor PM2.5 (fine particulate matter with an aerodynamic diameter smaller than 2.5 µm) concentration for both the heating and non-heating seasons. Combining this dataset with time-activity patterns and percentage of households using solid fuels, we assess the population-weighted annual mean exposure to PM2.5 (PWE) and the health impacts associated with HAP in mainland rural China by county for the year 2010. We find that ignoring heating impacts leads to an underestimation in PWE estimates by 38 µg/m3 for the nationwide rural population (16 to 40 as interquartile range) with substantial negative bias in northern provinces. Correspondingly, premature deaths and disability-adjusted life years will be underestimated by approximately 30 × 103 and 60 × 104 in 2010, respectively. Our study poses the need for incorporating heating effects into HAP risk assessments in China as well as globally.


Assuntos
Poluição do Ar em Ambientes Fechados/análise , Exposição Ambiental , Material Particulado/análise , China , Exposição Ambiental/análise , Exposição Ambiental/estatística & dados numéricos , Humanos , População Rural
18.
Environ Sci Pollut Res Int ; 25(24): 23833-23844, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29876857

RESUMO

In recent years, ambient air has been severely contaminated by particulate matters (PMs) and some gas pollutants (nitrogen dioxide (NO2) and sulfur dioxide (SO2)) in China, and many studies have demonstrated that exposure to these pollutants can induce great adverse impacts on human health. The concentrations of the pollutants were much higher in winter than those in summer, and the average concentrations in this studied area were lower than those in northern China. In the comparison between high-resolution emission inventory and spatial distribution of PM2.5, significant positive linear correlation was found. Though the pollutants had similar trends, NO2 and SO2 delayed with 1 h to PM2.5. Besides, PM2.5 had a lag time of 1 h to temperature and relative humidity. Significant linear correlation was found among pollutants and meteorological conditions, suggesting the impact of meteorological conditions on ambient air pollution other than emission. For the 24-h trend, lowest concentrations of PM2.5, NO2, and SO2 were found around 15:00-18:00. In 2015, the population attributable fractions (PAFs) for ischemic heart disease (IHD), cerebrovascular disease (stroke), chronic obstructive pulmonary disease (COPD), lung cancer (LC), and acute lower respiratory infection (ALRI) due to the exposure to PM2.5 in Zhejiang province were 25.82, 38.94, 17.73, 22.32, and 31.14%, respectively. The population-weighted mortality due to PM2.5 exposure in Zhejiang province was lower than the average level of the whole country-China.


Assuntos
Poluentes Atmosféricos/análise , Exposição Ambiental/efeitos adversos , Neoplasias Pulmonares/mortalidade , Isquemia Miocárdica/mortalidade , Doença Pulmonar Obstrutiva Crônica/mortalidade , Poluentes Atmosféricos/efeitos adversos , Poluição do Ar/efeitos adversos , Poluição do Ar/análise , Transtornos Cerebrovasculares/mortalidade , China/epidemiologia , Humanos , Conceitos Meteorológicos , Mortalidade , Dióxido de Nitrogênio/análise , Dióxido de Nitrogênio/toxicidade , Material Particulado/análise , Saúde Pública , Infecções Respiratórias/mortalidade , Estações do Ano , Dióxido de Enxofre/análise , Dióxido de Enxofre/toxicidade
19.
Appl Opt ; 57(11): 2947-2954, 2018 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-29714300

RESUMO

Off-axis integrated-cavity-output spectroscopy (OA-ICOS) is widely used in trace gas detection and isotopic analysis for its enhanced sensitivity as well as robustness against optical instability. However, its sensitivity is ultimately limited by the spurious coupling noise formed in the cavity, and much of the design and optimization process relies on empirical iterations while quantitative analysis is lacking. In this paper, we develop a method to model the optical field in OA-ICOS based on the decentered Gaussian beam model, which is a generalization for large tilting angles as compared with previously developed models. From the optical field, the cavity transmission spectrum for different cavity configurations or input beam conditions can be calculated, and the fringe noise level can be derived. Results show that an optimum combination of input laser beam and off-axis alignment exists to fully suppress the interference fringes. Factors affecting the fringe noise level, including a mismatch between the input beam and the cavity, optical alignment conditions, and deviation from the re-entrant condition, are studied thoroughly. The developed method can serve to guide the design and optimization of OA-ICOS systems.

20.
J Chromatogr Sci ; 56(8): 679-686, 2018 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-29718140

RESUMO

A poly(Methacrylate-co-Ethyleneglycol dimethacrylate) monolithic column was prepared in situ for high performance liquid chromatography and characterized utilizing scanning electron microscopy, thermodynamic parameters and linear solvation energy relationship methodology. The results revealed that there were many microglobules forming the larger cluster in poly(Methacrylate-co-Ethyleneglycol dimethacrylate) monolith prepared under the selected preparation conditions, which composed continuously aligned macroporous channels through the monolith skeleton. The poly(Methacrylate-co-Ethyleneglycol dimethacrylate) monolithic column had a good permeability, a high mechanical stability. The interaction model for each probe molecule on the poly(Methacrylate-co-Ethyleneglycol dimethacrylate) monolithic column was invariable within the studied temperature range due to an excellent linear relationship between lnk and 1/T for each probe molecule. The chromatographic retention for each probe molecule on the poly(Methacrylate-co-Ethyleneglycol dimethacrylate) monolithic column was an enthalpy-driven process due to |∆H°| > |T∆S°| and ∆G°<0. The main interaction forces of the poly(Methacrylate-co-Ethyleneglycol dimethacrylate) monolith with probe molecules contain hydrogen bonding interaction, hydrophobic interaction and dipole-dipole interaction. However, the contribution of each interaction was in the order of hydrogen bonding acidity > hydrophobic interactions > dipole-dipole interaction > hydrogen bonding basicity. In addition, the poly(Methacrylate-co-Ethyleneglycol dimethacrylate)monolithic column is suitable for the separation of both nonpolar and polar compounds.

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