Enhanced mitigation of inhalable particles and fine particle-bound PAHs from a novel hazardous waste-power plant candidate.

Emissions of the inhalable particle (dp < 10 µm, PM10) and their harmful compositions from combustion sources have high potential on health risk with nearly no regulation. This study investigates the particle size distribution (PSD), as well as the removal mechanism of PM10 and fine particle (FP)-bound polycyclic aromatic hydrocarbons (PAHs) from the flue gas of a hazardous waste thermal treatment system. It has ultralow regulated emission and becomes a candidate of power generation module. A series of the advanced scrubbers, cyclonic demister, and baghouse was equipped for multi-pollutant control. The moderate or intense low oxygen dilution (MILD) combustion effectively inhibited the PM2.5 generation by volumetric oxidation. Advanced scrubbers removed PM1, PM2.5, and PM10 by 85.24, 68.68, and 97.60%, respectively, which achieved by local supersaturation, heterogeneous condensation of water vapor, and the growth of fine PM. Moreover, the scrubbers effectively scavenged the course PM10 containing the high-molecular-weight PAH homologs onto the water phase but promoted the condensation and absorption of the lighter homologs onto the fine particle surface (dp ∼5.3 µm). The size window (dp = 0.3-1.0 µm) of the minimum efficiency reporting value of a BH filtration led to the peak of FP-PAH mass and BaP equivalent (BaPeq) toxicity at dp = 0.1-0.4 and 0.1-0.8 µm, respectively. Consequently, the synergy of MILD combustion and the SCB-CYC-BH system effectively inhibited the PM2.5, PM10, PM2.5-PAHs, and FP-PAH levels from a waste thermal treatment process and further mitigated the potential health risk.

Persistent Halogenated Organic Pollutants in Deep-Water-Deposited Particulates from South China Sea.

POP data are limited in the marine environment; thus, this study aimed to investigate background persistent organic pollutant (POP) levels in oceanic deep-water-deposited particulates in the South China Sea (SCS). Six POPs, including polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs), dioxin-like polychlorinated biphenyls (DL-PCBs), polybrominated diphenyl ethers (PBDEs), polybrominated dibenzo-p-dioxins/dibenzofurans (PBDD/Fs), polychlorinated diphenyl ethers (PCDEs), and polybrominated biphenyls (PBBs), were investigated in eight pooled samples from the SCS from 20 September 2013 to 23 March 2014 and 15 April 2014 to 24 October 2014 at depths of 2000 m and 3500 m. PBDEs were the most predominant compounds, with the highest mean Σ14PBDE of 125 ± 114 ng/g dry weight (d.w.), followed by Σ17PCDD/F, Σ12PBDD/F, and Σ12DL-PCB (275 ± 1930, 253 ± 216, and 116 ± 166 pg/g d.w., respectively). Most PBDD/F, PBB, and PCDE congeners were below the detection limits. PCDDs had the highest toxic equivalency (TEQ), followed by PBDDs and DL-PCBs. Among the six POPs, PBDEs were the major components of the marine-deposited particles, regarding both concentrations and mass fluxes. Compared to 3500 m, PBDE levels were higher at a depth of 2000 m. PBDE mass fluxes were 20.9 and 14.2 ng/m2/day or 68.2 and 75.9 ng/m2/year at deep-water 2000 and 3500 m, respectively. This study first investigated POP levels in oceanic deep-water-deposited particles from existing global data.

Low-temperature biochar production from torrefaction for wastewater treatment: A review.

Biochar, a carbon-rich and por ous material derived from waste biomass resources, has demonstrated tremendous potential in wastewater treatment. Torrefaction technology offers a favorable low-temperature biochar production method, and torrefied biochar can be used not only as a solid biofuel but also as a pollutant adsorbent. This review compares torrefaction technology with other thermochemical processes and discusses recent advancements in torrefaction techniques. Additionally, the applications of torrefied biochar in wastewater treatment (dyes, oil spills, heavy metals, and emerging pollutants) are comprehensively explored. Many studies have shown that high productivity, high survival of oxygen-containing functional groups, low temperature, and low energy consumption of dried biochar production make it attractive as an adsorbent for wastewater treatment. Moreover, used biochar's treatment, reuse, and safe disposal are introduced, providing valuable insights and contributions to developing sustainable environmental remediation strategies by biochar.

Using cluster algorithms with a machine learning technique and PMF models to quantify local-specific origins of PM2.5 and associated metals in Taiwan.

The influence of long-range transport (LRT) of air pollutants on neighboring regions and countries has been documented. The magnitude of LRT aerosols and related constituents can misdirect control strategies for local air quality management. In this study, we aimed to quantify PM2.5 (diameter less than 2.5 µm, PM2.5) and associated metals derived from local sources and LRT in different geographic locations in Taiwan using advanced receptor models. We collected daily PM2.5 samples (n = âˆ¼1000) and analyzed 28 metals every three days from 2016 to 2018 in the northern, central-south, eastern, and southern areas of Taiwan. We first used a machine learning technique with a cluster algorithm coupled with a backward trajectory to classify local, regional, and LRT-related aerosols. We then quantified the source contributions with a positive matrix factorization (PMF) model for Taiwan weighted by region-specific populations. The northern and eastern regions were found to be more vulnerable to LRT-related PM2.5 and metals than the central-south and southern regions in Taiwan. The LRT increased Pb and As concentrations by 90-200% and ∼40% in the northern and central-south regions. Ambient PM2.5-metals mainly originated from local traffic-related emissions in the northern, central-south, and southern regions, whereas oil combustion was the primary source of PM2.5-metals in the eastern region. By subtracting the influence from the LRT, the contributions of domestic emission sources to ambient PM2.5 metals in Taiwan were 35% from traffic-related emission, 17% from non-ferrous metallurgy, 13% from iron ore and steel factories, 12% from coal combustion, 12% from oil combustion, 10% from incinerator emissions, and <1% from cement manufacturing emissions. This study proposed an advanced method for refining local source contributions to ambient PM2.5 metals in Taiwan, which provides useful information on regional control strategies.

Effects of fuel injection system and exhaust gas catalytic treatments on PAH emissions from motorcycles.

The motorcycles are unignorable near-ground pollutant emission sources that increase the human exposure in the dense area. However, the information of the polycyclic aromatic hydrocarbons (PAHs) emissions under different scenarios of engine and emission control for motorcycle is limited. This study focused on the PAH emissions from two fuel-injection types of motorcycles, including the premixed fuel-injection (PFi) with carburetor and electronic fuel-injection (EFi). Specifically, the effects of throttle opening (TO), secondary air system (SAS), oxygen sensor (OS), oxidation catalytic converter (OCC), and three-way catalytic converter (TWC) on PAH emissions are investigated. Results show that the PAH emission concentrations increase 227-727%, 351-492%, and 155-408% by the increasing TO ratio, unworking SAS, and OS units in both motorcycles. For the PFi engine, the OCC unit is found to be more effective in PAH control (31-89%) than the SAS system (72-80%), especially under low TO operation. For the EFi engine which dominates the motorcycle market recently, the oxygen sensor for more accurate combustion control shows a better PAH reduction (36-76%) than TWC system (21-66%). The ultra-fine particulate phase PAHs, which is hardly removed by catalyst, needs to be further considered. Moreover, the total PAH emission level of the EFi engine is still about ten times higher than that of the PFi. By the annual emission calculation for three densely populated countries, the recent evolution significantly reduces the annual hydrocarbon (HC), carbon monoxide (CO), and nitrogen oxide (NOx) emissions but have unignorable PAH emissions. These emissions continuously affect the human health in the near-ground urban air and need to be considered in the next generation of motorcycle design.

Biohydrogen in a circular bioeconomy: A critical review.

Hydrogen produced from biomass feedstocks is considered an effective solution in moving toward a decarbonized economy. Biohydrogen is a clean energy source that has gained global attention for adoption as it promises to mitigate climate change and human environmental damage. Through the circular economy framework, sustainable biohydrogen production with other bioproducts while addressing issues such as waste management is possible. This study presents a comprehensive review of the various biomass feedstocks and processing technologies associated with biohydrogen generation, as well as the possible integration of existing industries into a circular bioeconomy framework. The currently standing challenges and future perspectives are also discussed.

Particulate PCDD/F size distribution and potential deposition in respiratory system from a hazardous waste thermal treatment process.

The particulate polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) of various sizes produced from the waste incinerators might have different toxicities, deposition characteristics, and potential health effects in the respiratory system, and their total toxicity equivalent (TEQ) concentration has been strictly regulated in recent years. There is a knowledge gap on the effects of air pollution control devices on particle size distributions (PSDs) of PCDD/Fs and their TEQ deposition. A hazardous waste thermal treatment plant equipped with an advanced scrubber, a cyclone demister, and activated carbon adsorption coupled with a baghouse filtration was investigated in this study. An 8-stage impactor was used to collect the particle distribution of PM10 and bounded PCDD/Fs from the gas stream at four sampling points located before and after each control unit. A "TEQDE" index is defined for the toxicity deposition of PM10-PCDD/F in the respiratory system. The advanced scrubbers significantly reduced the PM10-PCDD/F levels, especially for those with sizes ≥0.6 and ≤ 0.4 µm. Additionally, the cyclone also showed a better performance than the general dry gas treatment but had an efficiency drop with 1.5-4 µm particles. The PM10-PCDD/F loads in the final adsorption-filtration unit were eased and effectively removed the PM10-PCDD/Fs to sizes ≤0.5 or≥1.5 µm. The total TEQDE was 0.00052 ng WHO-TEQ Nm-3 and had a peak level of 0.000157 ng WHO-TEQ Nm-3 at 1.2 µm. PSDs were more sensitive to the PSDs of PM mass at high PM levels but strongly correlated with the PSDs of "PM10-PCDD/Fs/PM10" at low PM10 loads. Consequently, the advanced control system could effectively remove the PM10-PCDD/Fs and might extend the adsorption-filtration lifetime. However, the PM10-PCDD/Fs ≤ 0.4 µm had a higher TEQ deposition rate and should be further considered in emissions and ambient air quality evaluations.

Pretreatment, modification and applications of sewage sludge-derived biochar for resource recovery- A review.

With the quick increase in industrialization and urbanization, a mass of sludge has been produced on the account of increased wastewater treatment facilities. Sewage sludge (SS) management has become one of the most crucial environmental problems because of the existence of various pollutants. However, SS is a carbon-rich material, which has favored novel technologies for biochar production, which can be utilized for dissimilar applications. This review systematically analyzes and summarizes the pretreatment, modification, and especially application of sewage sludge-derived biochar (SSBC), based on published literature. The comparative assessment of pretreatment technology such as pyrolysis, hydrothermal carbonization, combustion, deashing, and co-feeding is presented to appraise their appropriateness for SS resource availability and the production of SSBC. In addition, the authors summarize and analyze the current modification methods and divide them into two categories: physical properties and surface chemical modifications. The applications of SSBC as absorbent, catalyst and catalyst support, electrode materials, gas storage, soil amendment, and sold biofuel are reviewed in detail. Furthermore, the discussion about the existing problems and the direction of future efforts are presented at the end of each section to envisage SS as a promising opportunity for resources rather than a nuisance.

Ultra-low PCDD/F emissions and their particle size and mass distribution in a hazardous waste treatment system.

An integrated gasification-flameless combustion-melting process was approached by a twin-cyclonic flow in a hazardous waste thermal treatment plant. A series of advanced scrubber, cyclonic demister, activated carbon adsorption, and baghouse processes were equipped for the end-of-pipe treatment. The untreated filterable particulate matter, CO, and NOx levels were only 283, 47.1, and 15.9 mg/Nm3, indicating the flameless combustion inhibited their formation by narrowing the post-combustion zone. The filterable particle mass-size distribution was equally contributed by nucleation, accumulation, and coarse formations, while their number concentration was predominated by nucleation (99.6%). That could enhance the adsorption of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) on ultrafine particles. Both total mass and toxic equivalent concentrations of PCDD/Fs were reduced 99.9% by the new air pollution control system when a slight reformation occurred during scrubbing. However, the escaped PCDD/Fs were mainly distributed on the ultrafine particles, which should be further inhibited by either increasing their sizes or equipping backup filtrations. Finally, the new process concentrates the PCDD/Fs into the scrubbing sludge, which could be recirculated back into the thermal process. This study not only reveals the emission risk of the ultrafine particle-bound PCDD/Fs, but also provides an effective process to remove them for industrial application.

Use of hydrous ABE-glycerin-diesel microemulsions in a nonroad diesel engine - Performance and unignorable emissions.

Oversupply, extra energy consumption, and CO2 emissions from the refinery of biodiesel-derived glycerin (G) led to the consideration of its use as an alternative fuel. In this study, a nonroad diesel engine generator was employed to represent potential emissions under stringent regulated standards. G-diesel has been reported to reduce nitrogen oxides (NOx) and soot levels but increase CO and hydrocarbon emissions. A bio-producible acetone-butanol-ethanol (ABE) solution with multiple polarities was added to stabilize the glycerin and water in diesel examined in this study. A series of ABE-G-diesel blends were prepared to form the thermostable microemulsions. Four blends with small and well-dispersed bubbles were tested in the engine generator. The specific thermal efficiencies of the engine were slightly improved by using ABE-G from regular diesel due to better spray quality, longer ignition delay, and fuel-oxygen content that would enhance combustion. Meanwhile, the PM-NOx-CO emission trade-off in the previous study has been overcome by using ABE-G-diesel since the better fuel atomization and more premixed combustion were approached, as well as the lower and homogeneous in-cylinder temperature caused by water content and micro-explosion. However, the condensable particulate matter and nitro-PAHs were also observed and realized their unignorable contribution, which has not been regulated and even researched for the generators. Fortunately, the new fuels could inhibit both of them to a certain degree. Consequently, this study proposes using recyclable glycerin with a simple pretreatment mixed with ABE and diesel for greener nonroad diesel engine especially those equipped with low-grade aftertreatment.

Numerical Investigation of Negative Temperature Coefficient Effects on Sooting Characteristics in a Laminar Co-flow Diffusion Flame.

It is a common sense that diesel engines produce worse soot emission than gasoline engines, even though gasoline direct injection also brings about terrible sooting tendency. However, reports showed that diesel emits less soot than gasoline in laminar diffusion flames, which implies that soot emission is a combined effect of multiple factors, such as the combustion mode, physical properties of the fuel, and also fuel chemistry. This work, thus, conducted numerical calculations in laminar co-flow diffusion flames of fuels with different negative temperature coefficient (NTC) behaviors in an order of n-heptane > iso-octane > toluene to solely evaluate the chemical effect, especially the role of low-temperature combustion on soot formation. 2-Dimensional simulations were carried out to obtain the soot distributions, and 0-dimensional simulations were performed to analyze the chemical kinetics of polycyclic aromatic hydrocarbon (PAH) formation and low-temperature reaction sensitivities. The grids of the 2-D model converged at 80(r) × 196(z), and the boundary conditions of both models were set to eliminate the influence of physical factors as much as possible. The results showed that there were three main reactions associated to the formation of aromatic hydrocarbons A1 at the first-stage combustion in the n-heptane flame and the iso-octane flame, in which the reaction of C7H15 + O2 = C7H15O2 enhances the NTC behavior. The first two reaction pathways generated larger molecular hydrocarbons and were unfavorable by A1 formation and therefore inhabit the PAH formation, and 49.8% of C7H16 reacted through the large molecular pathways, while the percentage for C8H18, with weaker NTC behavior, was only 37%. Toluene with even weaker NTC behavior showed no low-temperature oxidation. Therefore, in a more general case, fuels with stronger NTC behavior smoke less, and this conclusion could be promising potential to reduce soot emission in future.

A novel flameless oxidation and in-chamber melting system coupled with advanced scrubbers for a laboratory waste plant.

This is the first study integrate the flameless oxidation (FO) and in-chamber melting (ICM) processes in a primary chamber of a laboratory waste incinerator to improve energy and emission performances. Two liquid burners created a twin-cyclonic fluid field that achieved the FO and ICM in the same chamber. The first cyclone provided a well-mixed and lower temperature FO to reduce auxiliary diesel consumption, NOx and PM emissions by 25.8%, 30.9%, and 79.2%, respectively, from the original system. The hot gases produced by FO enhance the ICM process and transformed the bottom ashes to stabler slags, in turn meeting the regulations for nonhazardous wastes. The other cyclone enhanced the drying and water-gas shift reaction in the drying zone by recirculating the CO and enthalpy from FO and ICM. Eventually, the residual CO, hydrocarbons, and H2 were sent to the secondary chamber for further oxidation. A computational fluid dynamic simulation supported the fluid field assumption posed in this study. Moreover, advanced scrubbers were employed after thermal treatments to reduce HCl and SO2 by 81.8% and 38.8% and further retarded the corrosion rate in the baghouse supporting cage by 87.7%. The precursors of condensable particulate matter were reduced by condensation and finally removed in the baghouse. Nevertheless, the emissions of the high- and mid-molecular-weight polycyclic aromatic hydrocarbons were greatly reduced by 60.8-93.1% and 80.2-99.9%, respectively. Consequently, the new system reduced annual emissions by 40.7-87.6% and operating costs by 41.5%, allowing recovery of the remodification investment in 20.5 months.

Integrated analysis of source-specific risks for PM2.5-bound metals in urban, suburban, rural, and industrial areas.

The levels and characteristics of atmospheric metals vary in time and location, can result in various health impacts, which increases the challenge of air quality management. We aimed to investigate PM2.5-bound metals in multiple locations and propose a methodology for comparing metal elements across study regions and prioritizing source contributions through integrated health risk assessments. PM2.5-bound metals were collected in the urban, suburban, rural, and industrial regions of Taiwan between 2016 and 2018. We incorporated the positive matrix factorization (PMF) with health risk assessments (considering estimates of the margin of exposure (MOE) and excess cancer risk (ECR)) to prioritize sources for control. We found that the concentrations of Fe, Zn, V, Cu, and Mn (industry-related metals) were higher at the industrial site (Kaohsiung) and Ba, Cr, Ni, Mo, and Co (traffic-related metals) were higher at the urban site (Taipei). The rural site (Hualian) had good air quality, with low PM2.5 and metal concentrations. Most metal concentrations were higher during the cold season for all study sites, except for the rural. Ambient concentrations of Mn, Cr, and Pb obtained from all study sites presents a higher health risk of concern. In Kaohsiung, south Taiwan, PM2.5-bound metals from the iron ore and steel factory is suggested as the first target for control based on the calculated health risks (MOE < 1 and ECR > 10-6). Overall, we proposed an integrated strategy for initiating the source management prioritization of PM2.5-bound metals, which can aid an effort for policymaking.

Toxicity assessment of electrochemical advanced oxidation process-treated groundwater from a gas station with petrochemical contamination.

Electrochemical advanced oxidation process (EAOP) is known for its efficient and fast degradation of organic pollutants in polluted water treatment. In this study, the EAOP using a boron-doped diamond (BDD) anode was applied to treat two-season groundwater samples collected from four sampling wells (GS1 to GS4) with petrochemical contaminants including methyl tert-butyl ether (MTBE), benzene, toluene, chlorobenzene, total organic compounds (TOC), and total petroleum hydrocarbons (TPH) at a gas station in southern Taiwan. Moreover, toxicity tests (ATP, p53, and NF-κB bioassays) were performed to evaluate the biological responses of raw and EAOP-treated groundwater. Results show that the concentrations of chlorobenzene before and after EAOP treatment were all below its method detection limit. High degradation efficiencies were observed for MTBE (100%), benzene (100%), toluene (100%, except that of GS2 in the first season), TPH (94-97%, except that of GS4 in the first season), and TOC (85-99%). Cell viability for both the raw groundwater (81.2 ± 13.5%) and EAOP-treated samples (84.7 ± 11.7%) as detected using the ATP bioassay showed no significant difference (p = 0.715). A mean reduction in the DNA damage (739 to 165 ng DOX-equivalency L-1 (ng DOX-EQ. L-1)) and inflammatory response levels (460 to 157 ng TNFα-equivalency L-1 (ng TNFα-EQ. L-1)) were observed for EAOP-treated samples subjected to p53 and NF-κB bioassays. Overall, the significances of the average degradation efficiency, DNA damage, and inflammatory response before and after groundwater with EAOP treatment was observed to be significant (p < 0.05). p53 and NF-κB bioassays might be applied to assess ecotoxic risk in the environment.

Data on greenhouse gases emission of fuels in power plants in Malaysia during the year of 1990-2017.

Energy has a significant influence on Malaysia's industry. It is used in electricity generation, refineries, gas processing plants and end-user applications such as transportation, residential, agriculture and fishing. These burning fossil fuel activities produce greenhouse gases (GHG) emissions. This article presents the emissions data of fuel used in power plants in Malaysia during the year of 1990 until 2017. The fuel used in power plants is coal and coke, natural gas, diesel oil and residual fuel oil. The energy data used in power plants were gathered from the Malaysia Energy Information Hub, published by the Malaysian Energy Commission. The GHG emissions data were calculated using the emission factors method. The climate impact of different GHGs in terms of CO2-equivalent (CO2-e) was also calculated using global warming potentials. The article also presents population data in Malaysia during the year. A correlation between the fuels, GHG emission and the population is also investigated using statistical analysis. The data presented here may facilitate the Malaysian government to identify the source of the pollutants and undertake a climate change mitigation plan.

Effects of a quenching treatment on PCDD/F reduction in the bottom ash of a lab waste incinerator to save the energy and cost incurred from post-thermal treatment.

Bottom ash (BA) from incineration has been reused as a construction material for years. However, thermal treatments, which incur extra cost and higher energy demand, are essential to reduce/stabilize the polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in BA, which can be released from BA during the next startup and cause peak emissions. In this study, the bottom ash from a laboratory waste incinerator (LWI) was collected and quenched at various temperatures during three shutdown operations to determine the results of the gradual cooling process. The PCDD/F content in the BA was quantified using gas chromatography-mass spectrometry. The PCDD/Fs in BA was significantly lower (0.0239 ng WHO-TEQ g-1) after being quenched at >400 °C, which was only 1/300 of that in the sample gradually cooled to <200 °C (6.21 ng WHO-TEQ g-1). The PCDD/PCDF ratios were less than 1 in all of the samples, suggesting that de novo synthesis might be the predominant formation mechanism, and exponential relationships between the PCDD/F growth ratio and quenching temperature were found, with an r2 > 0.97. In other words, careful operation of the cooling process is an important PCDD/F inhibition strategy and effectively reduces the subsequent startup emissions. Interestingly, the extremely low PCDD/F levels in the BA after quenching were found to further save the cost of thermal treatment, reduce electricity use by 500 MWh, and lower fuel consumption by 27 kL of diesel, as well as reducing annual CO2e emissions by 351 tons in an LWI. This finding could be further applied to simultaneously control PCDD/F emissions, save post-treatment costs, and reduce the secondary pollutants in other incinerators.

Residue Levels of Organochlorine Pesticides in Breast Milk and Its Associations with Cord Blood Thyroid Hormones and the Offspring's Neurodevelopment.

Previous studies have demonstrated that organochlorine pesticide (OCP) exposure has a negative impact on the neurological function of infants. Only a few reports have investigated the thyroid and growth hormones and their relationship to neurodevelopment after human exposure to OCPs, especially in the case of infants. Our goal was to determine whether breastmilk OCP residues were associated with negative impacts and/or alterations in the neurodevelopment of infants among specific southern Taiwanese mother-breastfed infant pairs. Our subjects (n = 55 pairs) were recruited from southern Taiwan between 2007 and 2010. The thyroid and growth hormone levels in the cord blood samples collected after childbirth were determined. The breastmilk was gathered within one month after childbirth for the determination of OCP levels using a high-resolution gas chromatograph with mass spectrometry, and the neurodevelopment of 10-12-month-old infants was examined using the Bayley Scales of Infant and Toddler Development®, Third Edition (Bayley-III). It was observed that 4,4'-dichlorodiphenyl-dichloroethylene (4,4'-DDE) (mean = 10.3 ng/g lipid) was the most predominant OCP compound in the breastmilk samples. At higher concentrations (>75th percentile), specific OCPs were associated with significantly lower levels of thyroid and growth hormones than at lower concentrations (<75th percentile). Significantly higher odds ratios (ORs) were observed for binary cognitive (OR = 8.09, p = 0.025 for 4,4'-DDT), language (OR = 11.9, p = 0.013 for 4,4'-DDT) and social-emotional (OR = 6.06, p = 0.01 for trans-CHL) composite scores for specific OCPs belonging to the lower exposure group as compared to the higher OCP exposure group. The five domain Bayley-III infant neurodevelopment outcomes were negatively associated with specific OCPs in the breast milk samples based on the redundancy analysis (RDA) test. Bayley-III scales, which include cognitive, language, motor, social-emotional, and adaptive behavior scales, could be predicted by 4,4'-DDT, endrin, endosulfan I, heptachlor, or heptachlor epoxide using multivariate linear regression models with adjustment for maternal age, pre-pregnant BMI, parity, and infant gender. In conclusion, although our study showed that postnatal exposure to breast milk OCPs may be associated with infant neurodevelopmental outcomes and that prenatal exposure, if extrapolated from breastmilk levels, is associated with changes in thyroid and growth hormones that may have effects on neurodevelopment, these associations are only suggestive; thus, further studies are recommended for confirmation.

Reduction of atmospheric fine particle level by restricting the idling vehicles around a sensitive area.

Atmospheric particles are a major problem that could lead to harmful effects on human health, especially in densely populated urban areas. Chiayi is a typical city with very high population and traffic density, as well as being located at the downwind side of several pollution sources. Multiple contributors for PM2.5 (particulate matter with an aerodynamic diameter ≥2.5 µm) and ultrafine particles cause complicated air quality problems. This study focused on the inhibition of local emission sources by restricting the idling vehicles around a school area and evaluating the changes in surrounding atmospheric PM conditions. Two stationary sites were monitored, including a background site on the upwind side of the school and a campus site inside the school, to monitor the exposure level, before and after the idling prohibition. In the base condition, the PM2.5 mass concentrations were found to increase 15% from the background, whereas the nitrate (NO3-) content had a significant increase at the campus site. The anthropogenic metal contents in PM2.5 were higher at the campus site than the background site. Mobile emissions were found to be the most likely contributor to the school hot spot area by chemical mass balance modeling (CMB8.2). On the other hand, the PM2.5 in the school campus fell to only 2% after idling vehicle control, when the mobile source contribution reduced from 42.8% to 36.7%. The mobile monitoring also showed significant reductions in atmospheric PM2.5, PM0.1, polycyclic aromatic hydrocarbons (PAHs), and black carbon (BC) levels by 16.5%, 33.3%, 48.0%, and 11.5%, respectively. Consequently, the restriction of local idling emission was proven to significantly reduce PM and harmful pollutants in the hot spots around the school environment. IMPLICATIONS: The emission of idling vehicles strongly affects the levels of particles and relative pollutants in near-ground air around a school area. The PM2.5 mass concentration at a campus site increased from the background site by 15%, whereas NO3- and anthropogenic metals also significantly increased. Meanwhile, the PM2.5 contribution from mobile source in the campus increased 6.6% from the upwind site. An idling prohibition took place and showed impressive results. Reductions of PM2.5, ionic component, and non-natural metal contents were found after the idling prohibition. The mobile monitoring also pointed out a significant improvement with the spatial analysis of PM2.5, PM0.1, PAH, and black carbon concentrations. These findings are very useful to effectively improve the local air quality of a densely city during the rush hour.

Ambient PM2.5 in the residential area near industrial complexes: Spatiotemporal variation, source apportionment, and health impact.

This study systemically investigated the ambient PM2.5 (n=108) with comprehensive analyses of the chemical composition, identification of the potential contributors, and estimation of the resultant respiratory physician visits in the residential regions near energy-consuming and high-polluting industries in central Taiwan. The positive matrix fraction (PMF) model with chemical profiles of trace metals, water-soluble ions, and organic/elemental carbons (OC/EC) was applied to quantify the potential sources of PM2.5. The influences of local sources were also explored using the conditional probability function (CPF). Associations between the daily PM2.5 concentration and the risk of respiratory physician visits for the elderly (≥65years of age) were estimated using time-series analysis. A seasonal variation, with higher concentrations of PM2.5, metals (As, Cd, Sb, and Pb), OC/EC and ions (i.e., NO3-, SO42- and NH4+) in the winter than in the spring and summer, was observed. Overall, an increase of 10µgm-3 in the same-day PM2.5 was associated with an ~2% (95% CI: 1.5%-2.5%) increase in respiratory physician visits. Considering the health benefits of an effective reduction, we suggest that the emission from coal combustion (23.5%), iron ore and steel industry (17.1%), and non-ferrous metallurgy (14.4%), accounting for ~70% of the primary PM2.5 in the winter are prioritized to control.

Elemental characterization and source apportionment of PM10 and PM2.5 in the western coastal area of central Taiwan.

This study investigated seasonal variations in PM10 and PM2.5 mass and associated trace metal concentrations in a residential area in proximity to the crude oil refinery plants and industrial parks of central Taiwan. Particle measurements were conducted during winter, spring and summer in 2013 and 2014. Twenty-six trace metals in PM10 and PM2.5 were analyzed using ICP-MS. Multiple approaches of the backward trajectory model, enrichment factor (EF), Lanthanum enrichment and positive matrix fraction (PMF) were used to identify potential sources of particulate metals. Mean concentrations of PM10 in winter, spring and summer were 76.4 ± 22.6, 33.2 ± 9.9 and 37.4 ± 17.0 µg m(-3), respectively, while mean levels of PM2.5 in winter, spring and summer were 47.8 ± 20.0, 23.9 ± 11.2 and 16.3 ± 8.2 µg m(-3), respectively. The concentrations of carcinogenic metals (Ni, As and adjusted Cr(VI)) in PM10 and PM2.5 exceeded the guideline limits published by WHO. The result of EF analysis confirmed that Mo, Sb, Cd, Zn, Mg, Cr, As, Pb, Cu, Ni and V were attributable to anthropogenic emission. PMF analysis demonstrated that trace metals in PM10 and PM2.5 were from the similar sources, such as coal combustion, oil combustion and traffic-related emission, except for soil dust and crustal element emissions only observed in PM10 and secondary aluminum smelter only observed in PM2.5. Considering health-related particulate metals, the traffic-related emission and coal combustion for PM10 and PM2.5, respectively, are important to control for reducing potential carcinogenic risk. The results could aid efforts to clarify the impact of source-specific origins on human health.