Toxics

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27 pages, 720 KiB

Open AccessArticle

Local Scale Exposure and Fate of Engineered Nanomaterials

by Mikko Poikkimäki, Joris T. K. Quik, Arto Säämänen and Miikka Dal Maso

Toxics 2022, 10(7), 354; https://doi.org/10.3390/toxics10070354 - 29 Jun 2022

Cited by 1 | Viewed by 2860

Nanotechnology is a growing megatrend in industrial production and innovations. Many applications utilize engineered nanomaterials (ENMs) that are potentially released into the atmospheric environment, e.g., via direct stack emissions from production facilities. Limited information exists on adverse effects such ENM releases may have [...] Read more.

Nanotechnology is a growing megatrend in industrial production and innovations. Many applications utilize engineered nanomaterials (ENMs) that are potentially released into the atmospheric environment, e.g., via direct stack emissions from production facilities. Limited information exists on adverse effects such ENM releases may have on human health and the environment. Previous exposure modeling approaches have focused on large regional compartments, into which the released ENMs are evenly mixed. However, due to the localization of the ENM release and removal processes, potentially higher airborne concentrations and deposition fluxes are obtained around the production facilities. Therefore, we compare the ENM concentrations from a dispersion model to those from the uniformly mixed compartment approach. For realistic release scenarios, we based the modeling on the case study measurement data from two TiO

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nanomaterial handling facilities. In addition, we calculated the distances, at which 50% of the ENMs are deposited, serving as a physically relevant metric to separate the local scale from the regional scale, thus indicating the size of the high exposure and risk region near the facility. As a result, we suggest a local scale compartment to be implemented in the multicompartment nanomaterial exposure models. We also present a computational tool for local exposure assessment that could be included to regulatory guidance and existing risk governance networks. Full article

(This article belongs to the Special Issue Sources, Atmospheric Transformation and Dispersion of Aerosol Particles)

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21 pages, 5539 KiB

Open AccessArticle

Simulating PM_2.5 Concentrations during New Year in Cuenca, Ecuador: Effects of Advancing the Time of Burning Activities

by René Parra, Claudia Saud and Claudia Espinoza

Toxics 2022, 10(5), 264; https://doi.org/10.3390/toxics10050264 - 19 May 2022

Cited by 4 | Viewed by 2284

Abstract

Fine particulate matter (PM_2.5) is dangerous to human health. At midnight on 31 December, in Ecuadorian cities, people burn puppets and fireworks, emitting high amounts of PM_2.5. On 1 January 2022, concentrations between 27.3 and 40.6 µg m⁻³ [...] Read more.

Fine particulate matter (PM_2.5) is dangerous to human health. At midnight on 31 December, in Ecuadorian cities, people burn puppets and fireworks, emitting high amounts of PM_2.5. On 1 January 2022, concentrations between 27.3 and 40.6 µg m⁻³ (maximum mean over 24 h) were measured in Cuenca, an Andean city located in southern Ecuador; these are higher than 15 µg m⁻³, the current World Health Organization guideline. We estimated the corresponding PM_2.5 emissions and used them as an input to the Weather Research and Forecasting with Chemistry (WRF-Chem 3.2) model to simulate the change in PM_2.5 concentrations, assuming these emissions started at 18:00 LT or 21:00 LT on 31 December 2021. On average, PM_2.5 concentrations decreased by 51.4% and 33.2%. Similar modeling exercises were completed for 2016 to 2021, providing mean decreases between 21.4% and 61.0% if emissions started at 18:00 LT. Lower mean reductions, between 2.3% and 40.7%, or even local increases, were computed for emissions beginning at 21:00 LT. Reductions occurred through better atmospheric conditions to disperse PM_2.5 compared to midnight. Advancing the burning time can help reduce the health effects of PM_2.5 emissions on 31 December. Full article

(This article belongs to the Special Issue Sources, Atmospheric Transformation and Dispersion of Aerosol Particles)

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12 pages, 6389 KiB

Open AccessArticle

Seasonal Distribution of Atmospheric Coarse and Fine Particulate Matter in a Medium-Sized City of Northern China

by Xin Zhang, Bianhong Zhou, Zhiyu Li, Yue Lin, Lijuan Li and Yuemei Han

Toxics 2022, 10(5), 216; https://doi.org/10.3390/toxics10050216 - 25 Apr 2022

Cited by 7 | Viewed by 2080

Abstract

Atmospheric particulate matter (PM) was measured continuously at an urban site in Baoji city in northern China in 2018 to investigate the seasonal distribution characteristics. Coarse PM (PM_2.5–10) was more prevalent in spring, substantially due to the regional transport of dust. [...] Read more.

Atmospheric particulate matter (PM) was measured continuously at an urban site in Baoji city in northern China in 2018 to investigate the seasonal distribution characteristics. Coarse PM (PM_2.5–10) was more prevalent in spring, substantially due to the regional transport of dust. High loadings of coarse PM were found at night compared to daytime, which could result from high production and unfavorable dispersion conditions. Fine PM (PM_2.5) constituted, on average, 54% of the total PM mass concentration, whereas it contributed more than 97% of the total PM number concentration. The number and mass concentrations of fine PM increased substantially in the winter, which was possibly due to the enhanced production of atmospheric secondary processes and coal combustion. Precursor gaseous pollutants and meteorology greatly influenced the PM distributions. Fine PM was associated more strongly with gas pollutants than coarse PM, which suggested that it largely originated from secondary production and combustion sources. High relative humidity appeared to promote the production of fine PM, whereas it facilitated the removal of coarse PM. This study highlights that different air-pollution control strategies should be used for coarse and fine PM according to the distribution characteristics and influencing factors in similar medium-sized urban areas. Full article

(This article belongs to the Special Issue Sources, Atmospheric Transformation and Dispersion of Aerosol Particles)

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15 pages, 1472 KiB

Open AccessArticle

Potential Risks of PM_2.5-Bound Polycyclic Aromatic Hydrocarbons and Heavy Metals from Inland and Marine Directions for a Marine Background Site in North China

by Qianqian Xue, Yingze Tian, Xinyi Liu, Xiaojun Wang, Bo Huang, Hongxia Zhu and Yinchang Feng

Toxics 2022, 10(1), 32; https://doi.org/10.3390/toxics10010032 - 11 Jan 2022

Cited by 12 | Viewed by 2243

Abstract

Ambient PM_2.5-bound ions, OC, EC, heavy metals (HMs), 18 polycyclic aromatic hydrocarbons (PAHs), 7 hopanes, and 29 n-alkanes were detected at Tuoji Island (TI), the only marine background atmospheric monitoring station in North China. The annual PM_2.5 average concentration was [...] Read more.

Ambient PM_2.5-bound ions, OC, EC, heavy metals (HMs), 18 polycyclic aromatic hydrocarbons (PAHs), 7 hopanes, and 29 n-alkanes were detected at Tuoji Island (TI), the only marine background atmospheric monitoring station in North China. The annual PM_2.5 average concentration was 47 ± 31 μg m⁻³, and the average concentrations of the compositions in PM_2.5 were higher in cold seasons than in warm seasons. The cancer and non-cancer risks of HMs and PAHs in cold seasons were also higher than in warm seasons. BaP, Ni, and As dominated the ∑HQ (hazard quotient) in cold seasons, while the non-carcinogenic risk in warm seasons was mainly dominated by Ni, Mn, and As. The ILCR (incremental lifetime cancer risk) values associated with Cr and As were higher in the cold season, while ILCR-Ni values were higher in the warm season. The backward trajectory was calculated to identify the potential directions of air mass at TI. Through the diagnostic ratios of organic and inorganic tracers, the sources of particulate matter in different directions were judged. It was found that ship emissions and sea salt were the main sources from marine directions, while coal combustion, vehicles emissions, industrial process, and secondary aerosols were the main source categories for inland directions. In addition, potential HM and PAH risks from inland and marine directions were explored. The non-cancerous effects of TI were mainly affected by inland transport, especially from the southeast, northwest, and west-northwest. The cancerous effects of TI were mainly simultaneously affected by the inland direction and marine direction of transport. Full article

(This article belongs to the Special Issue Sources, Atmospheric Transformation and Dispersion of Aerosol Particles)

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30 pages, 7005 KiB

Open AccessFeature PaperArticle

City Scale Modeling of Ultrafine Particles in Urban Areas with Special Focus on Passenger Ferryboat Emission Impact

by Marvin Lauenburg, Matthias Karl, Volker Matthias, Markus Quante and Martin Otto Paul Ramacher

Toxics 2022, 10(1), 3; https://doi.org/10.3390/toxics10010003 - 21 Dec 2021

Cited by 3 | Viewed by 5247

Abstract

Air pollution by aerosol particles is mainly monitored as mass concentrations of particulate matter, such as PM₁₀ and PM_2.5. However, mass-based measurements are hardly representative for ultrafine particles (UFP), which can only be monitored adequately by particle number (PN) concentrations [...] Read more.

Air pollution by aerosol particles is mainly monitored as mass concentrations of particulate matter, such as PM₁₀ and PM_2.5. However, mass-based measurements are hardly representative for ultrafine particles (UFP), which can only be monitored adequately by particle number (PN) concentrations and are considered particularly harmful to human health. This study examines the dispersion of UFP in Hamburg city center and, in particular, the impact of passenger ferryboats by modeling PN concentrations and compares concentrations to measured values. To this end, emissions inventories and emission size spectra for different emission sectors influencing concentrations in the city center were created, explicitly considering passenger ferryboat traffic as an additional emission source. The city-scale chemical transport model EPISODE-CityChem is applied for the first time to simulate PN concentrations and additionally, observations of total particle number counts are taken at four different sampling sites in the city. Modeled UFP concentrations are in the range of 1.5–3 × 10⁴ cm⁻³ at ferryboat piers and at the road traffic locations with particle sizes predominantly below 50 nm. Urban background concentrations are at 0.4–1.2 × 10⁴ cm⁻³ with a predominant particle size in the range 50–100 nm. Ferryboat traffic is a significant source of emissions near the shore along the regular ferry routes. Modeled concentrations show slight differences to measured data, but the model is capable of reproducing the observed spatial variation of UFP concentrations. UFP show strong variations in both space and time, with day-to-day variations mainly controlled by differences in air temperature, wind speed and wind direction. Further model simulations should focus on longer periods of time to better understand the influence of meteorological conditions on UFP dynamics. Full article

(This article belongs to the Special Issue Sources, Atmospheric Transformation and Dispersion of Aerosol Particles)

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18 pages, 7126 KiB

Open AccessArticle

Contributions of Traffic and Industrial Emission Reductions to the Air Quality Improvement after the Lockdown of Wuhan and Neighboring Cities Due to COVID-19

by Xiaoxiao Feng, Xiaole Zhang, Cenlin He and Jing Wang

Toxics 2021, 9(12), 358; https://doi.org/10.3390/toxics9120358 - 17 Dec 2021

Cited by 12 | Viewed by 2809

Abstract

Wuhan was locked down from 23 January to 8 April 2020 to prevent the spread of the novel coronavirus disease 2019 (COVID-19). Both public and private transportation in Wuhan and its neighboring cities in Hubei Province were suspended or restricted, and the manufacturing [...] Read more.

Wuhan was locked down from 23 January to 8 April 2020 to prevent the spread of the novel coronavirus disease 2019 (COVID-19). Both public and private transportation in Wuhan and its neighboring cities in Hubei Province were suspended or restricted, and the manufacturing industry was partially shut down. This study collected and investigated ground monitoring data to prove that the lockdowns of the cities had significant influences on the air quality in Wuhan. The WRF-CMAQ (Weather Research and Forecasting-Community Multiscale Air Quality) model was used to evaluate the emission reduction from transportation and industry sectors and associated air quality impact. The results indicate that the reduction in traffic emission was nearly 100% immediately after the lockdown between 23 January and 8 February and that the industrial emission tended to decrease by about 50% during the same period. The industrial emission further deceased after 9 February. Emission reduction from transportation and that from industry was not simultaneous. The results imply that the shutdown of industry contributed significantly more to the pollutant reduction than the restricted transportation. Full article

(This article belongs to the Special Issue Sources, Atmospheric Transformation and Dispersion of Aerosol Particles)

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12 pages, 34741 KiB

Open AccessFeature PaperArticle

Air Quality in the Harbin-Changchun Metropolitan Area in Northeast China: Unique Episodes and New Trends

by Yulong Wang, Youwen Sun, Gerong Zhao and Yuan Cheng

Toxics 2021, 9(12), 357; https://doi.org/10.3390/toxics9120357 - 17 Dec 2021

Cited by 2 | Viewed by 2634

Abstract

Because of the unique geographical, climate, and anthropogenic emission characteristics, it is meaningful to explore the air pollution in the Harbin-Changchun (HC) metropolitan area. In this study, the Air Quality Index (AQI) and the corresponding major pollutant were investigated for the HC cities, [...] Read more.

Because of the unique geographical, climate, and anthropogenic emission characteristics, it is meaningful to explore the air pollution in the Harbin-Changchun (HC) metropolitan area. In this study, the Air Quality Index (AQI) and the corresponding major pollutant were investigated for the HC cities, based on the air quality data derived from the China National Environmental Monitoring Center. The number of days with the air quality level of “good” gradually increased during recent years, pointing to an improvement of the air quality in HC. It was also found that ozone, a typical secondary pollutant, exhibited stronger inter-city correlations compared to typical primary pollutants such as carbon monoxide and nitrogen dioxide. In addition, for nearly all the HC cities, the concentrations of fine particulate matter (PM_2.5) decreased substantially in 2020 compared to 2015. However, this was not the case for ozone, with the most significant increase of ozone observed for HC’s central city, Harbin. This study highlights the importance of ozone reduction for further improving HC’s air quality, and the importance of agricultural fire control for eliminating heavily-polluted and even off-the-charts PM_2.5 episodes. Full article

(This article belongs to the Special Issue Sources, Atmospheric Transformation and Dispersion of Aerosol Particles)

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22 pages, 4575 KiB

Open AccessFeature PaperArticle

Emissions Control Scenarios for Transport in Greater Cairo

by Rana Alaa Abbass, Prashant Kumar and Ahmed El-Gendy

Toxics 2021, 9(11), 285; https://doi.org/10.3390/toxics9110285 - 1 Nov 2021

Cited by 5 | Viewed by 4871

Abstract

Air pollution is a major cause of premature death in Greater Cairo, but studies on emission control are limited. We used local and international data to predict the impact of transport emission control measures on sector parameters including congestion. The International Vehicle Emission [...] Read more.

Air pollution is a major cause of premature death in Greater Cairo, but studies on emission control are limited. We used local and international data to predict the impact of transport emission control measures on sector parameters including congestion. The International Vehicle Emission model accordingly estimated quantities of criteria, toxic and global warming emissions produced by on-road vehicles. Emissions were estimated for 2019 base case (2019-BC) and projected for 2030 under the ‘do nothing’ scenario (2030-DNS) and five scenarios: fuel subsidy removal (2030-FSR), road expansions (2030-RE), public transport improvements (2030-PTI), inspection and maintenance (I/M) programs (2030-I/MP), and fuel enhancements (2030-FE). The 2030-FSR would reduce emissions by 11.2% versus 2030-DNS. The 2030-RE resulted in an average increase of 37% in emissions compared with 2030-DNS since it induces more traffic. The 2030-PTI provides alternatives to car travel; hence, cars result in an average drop of 32.8% for all emission types compared with 2030-DNS. The 2030-I/MP exhibited reductions in PM₁₀ and toxic pollutants, of 35–54.8% compared with 2030-DNS. The 2030-FE reduced SO_x, benzene and N₂O emissions by 91.8%, 81% and 39.1%, respectively, compared with 2030-DNS. The 2030-I/MP is most effective in reducing health damaging pollutants while 2030-PTI positively impacts commuters’ lifestyle. Full article

(This article belongs to the Special Issue Sources, Atmospheric Transformation and Dispersion of Aerosol Particles)

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