Simulation analysis of hazardous chemicals released from the furniture plant using ALOHA software.

The manufacturing of wooden furniture is extensive in Thailand's east. Hazardous chemicals were used in the wooden furniture industry's manufacturing process. Hazardous substances released into the surrounding atmosphere appear to have an impact on the environment and individuals. The ALOHA model is frequently used to assess hazardous chemicals released into the environment; this simulation model is an effective tool for modeling chemical compounds and detecting chemical disasters. It has a tremendous potential for preventing mishaps in potentially hazardous or emergency situations. Acetone and butyl acetate were extracted from the hardwood furniture business to identify accidents such as leaking, spillage, and evaporation. It is described as a highly poisonous, combustible, and explosive material. Toxic accident releases have negative implications for the surrounding areas. The goal of this work was to examine each accident using ALOHA software, and the computation of acetone and butyl acetate accidents was shown in this study. This project provides critical data for the furniture plant's chemical emergency rescue strategy as well as recommendations for emergency evacuation site decision-making.

Personal inhalation exposure to polycyclic aromatic hydrocarbons and their nitro-derivatives in rural residents in northern Thailand.

A personal inhalation exposure and cancer risk assessment of rural residents in Lampang, Thailand, was conducted for the first time. This highlighted important factors that may be associated with the highest areal incidence of lung cancer. Personal exposure of rural residents to polycyclic aromatic hydrocarbons (PAHs) and their nitro-derivatives (NPAHs) through inhalation of fine particulate matter (PM2.5) was investigated in addition to stationary air sampling in an urban area. The personal exposure of the subjects to PM2.5 ranged from 44.4 to 316 µg/m3, and the concentrations of PAHs (4.2-224 ng/m3) and NPAHs (120-1449 pg/m3) were higher than those at the urban site, indicating that personal exposure was affected by microenvironments through individual activities. The smoking behaviors of the rural residents barely affected their exposure to PAHs and NPAHs compared to other sources. The most important factor concerning the exposure of rural populations to PAHs was cooking activity, especially the use of charcoal open fires. The emission sources for rural residents and urban air were evaluated using diagnostic ratios, 1-nitropyrene/pyrene, and benzo[a]pyrene/benzo[ghi]perylene. Their analyses showed a significant contribution to emission from residents' personal activities in addition to the atmospheric environment. Furthermore, the personal inhalation cancer risks for all rural subjects exceeded the USEPA guideline value, suggesting that the residents have a potentially increased cancer risk. The use of open fires showed the highest cancer risk. A reduction in exposure to air pollutants for the residents could potentially be achieved by using clean fuel such as liquid petroleum gas or electricity for daily cooking.

The characteristics of carbonaceous particles down to the nanoparticle range in Rangsit city in the Bangkok Metropolitan Region, Thailand.

Atmospheric size-classified particles in sizes ranging from small to nanoparticles (PM0.1) are reported for Rangsit City in the Bangkok Metropolitan Region (BMR) of Thailand, for October 2019 (wet season) and January-February 2020 (dry season). The sampling involved the use of a PM0.1 cascade air sampler to determine the mass concentration. The PMs consisted of six stages including TSP-PM10, PM2.5-10, PM1.0-2.5, PM0.5-1.0, PM0.5-1.0 and PM0.1. Elemental carbon (EC) and organic carbon (OC) were evaluated by a carbon analyzer following the IMPROVE_TOR protocol. The average PM0.1 mass concentrations were found to be 13.47 ± 0.79 (wet season) and 18.88 ± 3.99 (dry season) µg/m3, respectively. The average OC/EC ratio for the rainy season was lower than that in the dry season. The char-EC/soot-EC ratios were consistently below 1 for the PM0.1 fraction in both seasons indicating that vehicular traffic appeared to be the main emission source. However, the influence of open biomass burning on fine and coarse PM particles on local air pollution was found to be an important issue during the wet season. In addition, long-range transport from other countries may also contribute to the carbon content in the Bangkok Metropolitan Region (BMR) atmosphere during the dry season. The higher secondary organic carbon to organic carbon (SOC/OC) ratio in the dry season is indicative of the contribution of secondary sources to the formation of PM, especially finer particles. A strong correlation between OC and EC in nanoparticles was found, indicating that they are derived from sources of constant emission, likely the diesel engines. Conversely, the OC and EC correlation for other size-specific PMs decreased during the dry season, indicating that these emission sources were more varied.

Emission Characteristics of Polycyclic Aromatic Hydrocarbons and Nitro-Polycyclic Aromatic Hydrocarbons from Open Burning of Rice Straw in the North of Vietnam.

This research investigated the distribution and contribution of polycyclic aromatic hydrocarbons (PAHs) and nitro-polycyclic aromatic hydrocarbons (NPAHs) bound to particulate matter (PM) emitted from open burning of rice straw (RS) into the atmosphere in the north of Vietnam. The experiments were conducted to collect PM2.5 and total suspended particulates (TSP) prior to and during burning in the period of 2016-2018 in suburban areas of Hanoi. Nine PAHs and 18 NPAHs were determined using the HPLC-FL system. The results showed that the proportion of RS burning seasonally affects the variation of PAHs emission in atmospheric environment. The levels of nine PAHs from RS burning were 254.4 ± 87.8 µg g-1 for PM2.5 and 209.7 ± 89.5 µg g-1 for TSP. We observed the fact that, although fluoranthene (Flu) was the most abundant PAH among detected PAHs both in PM2.5 and TSP, the enrichment of Flu in TSP from burning smoke was higher than that in PM2.5 while the contribution of benzo[a]pyrene (BaP) and indeno[1,2,3- cd]pyrene (IDP) in PM2.5 from burning smoke were much higher than those in TSP. This research found that 1-nitropyrene (1-NP) and 6-nitrochrysene (6-NC) emit from RS burning with the same range with those from wood burning. The 2-nitrofluorene (2-NF) and 2-nitropyrene (2-NP) released from RS burning as the secondary NPAHs. This research provides a comprehensive contribution characterization of PAHs and NPAHs in PM with different size emitted from traditional local rice straw burning in the north of Vietnam. The results help to clarify the environmental behavior of toxic organic compounds from RS burning in Southeast Asia.

Simultaneous determination of polycyclic aromatic hydrocarbon quinones by gas chromatography-tandem mass spectrometry, following a one-pot reductive trimethylsilyl derivatization.

We developed a sensitive and selective method to simultaneously analyze 37 polycyclic aromatic hydrocarbon quinones (PAHQs) with GC-MS/MS and applied the method to the analysis of standard atmospheric particulate matter samples. PAHQs were reduced with zinc granules and dithiothreitol (DTT) and the reductants were immediately converted to their silylated derivatives in a test tube. Two trimethylsilyl (TMS) groups were introduced into PAHQs through the one-pot reductive TMS derivatization. The PAHQs were derivatized with a mixed silylation reagent (BSA+TMCS+TMSI; (3:2:3)), which is one of the combinations of TMS-derivatization reagents with the highest reactivity. The derivatives produced different fragmentation between o-PAHQs and p-PAHQs. Therefore, isomers that have the same molecular weight are difficult to separate on a column were separated by the selected reaction monitoring (SRM) mode using the characteristic fragmentations, allowing separation and detection of all PAHQ derivatives in less than 30min. The instrumental detection limit (IDL) of each PAHQ was 1.2-29fg/injection and the method quantification limit (MQL) was 0.8-78µg/kg sample. For quantification, six deuterated PAHQs were used as internal standards to achieve high analytical precision. We applied the developed method to four standard atmospheric particulate matter samples. Results showed that out of 37 PAHQs, 33 compounds were identified and quantified. Moreover, from the 33 PAHQs, 14 were detected for the first time. Similar values were observed for the concentrations of PAHQs that have been quantified in previous reports. This method has the highest practicality in monitoring PAHQs in atmosphere, combustion exhaust gas, and toxicity evaluation. Thus, the method has the potential to become a standard analytical method for such applications.