Levels and health risks of PM2.5-bound toxic metals from firework/firecracker burning during festival periods in response to management strategies

Sources of acellular oxidative potential of water-soluble fine ambient particulate matter in the midwestern United States

Ambient fine particulate matter (PM2.5) is associated with numerous health complications, yet the specific PM2.5 chemical components and their emission sources contributing to these health outcomes are understudied. Our study analyzes the chemical composition of PM2.5 collected from five distinct locations at urban, roadside and rural environments in midwestern region of the United States, and associates them with five acellular oxidative potential (OP) endpoints of water-soluble PM2.5. Redox-active metals (i.e., Cu, Fe, and Mn) and carbonaceous species were correlated with most OP endpoints, suggesting their significant role in OP. We conducted a source apportionment analysis using positive matrix factorization (PMF) and found a strong disparity in the contribution of various emission sources to PM2.5 mass vs. OP. Regional secondary sources and combustion-related aerosols contributed significantly (> 75 % in total) to PM2.5 mass, but showed weaker contribution (43-69 %) to OP. Local sources such as parking emissions, industrial emissions, and agricultural activities, though accounting marginally to PM2.5 mass (< 10 % for each), significantly contributed to various OP endpoints (10-50 %). Our results demonstrate that the sources contributing to PM2.5 mass and health effects are not necessarily same, emphasizing the need for an improved air quality management strategy utilizing more health-relevant PM2.5 indicators.

Assessment of ambient air quality in relation to the burning of firecrackers during the festival of Diwali: A case study of Jodhpur City (India)

The study attempts to examine the impact of firework activities during Diwali Festival on ambient air quality of Jodhpur city. Air quality parameters particulate matter of diameter 10 μm (PM10), particulate matter of diameter 2.5 μm (PM2.5), sulfur dioxide (SO2), nitrogen dioxide (NO2) and heavy metals in PM2.5 like Pb, Ni, Ba, Al, As and Sr are monitored at two locations, for 15 days, starting from 7 days before the festival of Diwali, on the day of the festival (Diwali) and 7 days after Diwali. On the occasion of Diwali, it was discovered that the 24-h average levels of various pollutants were significantly elevated compared to regular days preceding the festival. Specifically, at the HBO site, the concentrations were notably increased, with sulfur dioxide (SO2) reaching 5.62 times higher, nitrogen dioxide (NO2) at 3 times higher, particulate matter of diameter 10 μm (PM10) at 2.35 times higher, and particulate matter of diameter 2.5 μm (PM2.5) at 1.01 times higher than the usual levels before Diwali. Similarly, at the PTMM site, there were substantial elevations in pollutant concentrations during Diwali compared to pre-festival days, with SO2 registering 2.53 times higher, NO2 at 2.37 times higher, PM2.5 at 1.9 times higher, and PM10 at 1.57 times higher levels than normal. Concentration of Al, Ba, Sr and Pb at HBO site and Al at PTMM site was highest on Diwali day. Air quality index which was in good category on normal days before Diwali, fell into poor category starting from the day before Diwali and remain in poor category on normal days after Diwali. The result indicates the worsening of ambient air quality during Diwali which can adversely impact the human health in terms of various respiratory complications.

Global, regional, and national burdens of intraocular foreign bodies in children and adolescents from 1990 to 2019: a trend analysis

BACKGROUND

This study aimed to evaluate trends in global, regional, and national burdens of intraocular foreign bodies among children and adolescents (aged 0 - 19 years) between 1990 and 2019 according to age, sex, and socio-demographic index.

METHODS

This study obtained data from the Global Burden of Disease Study 2019 and evaluated the number of cases, rates per 100,000 persons, and average annual percentage changes among children and adolescents. The annual percentage changes in the incidence and years lived with disability rates across various age groups were investigated using joinpoint software.

RESULTS

For intraocular foreign bodies in children and adolescents, the incidence and year lived with disability rates decreased in all age groups between 1990 and 2019. However, the number of incident cases and years lived with disability increased from 1091.94 [95% uncertainty interval (UI), 610.91-1839.52] and 89,245 (95% UI, 6.65-18.67) in 1990 to 1134.85 (95% UI, 665.01-1867.50) and 92,108 (95% UI, 32,052-192,153) in 2019, respectively. Age was positively correlated with the number of cases, incidence, and years lived with disability rates. However, there were significant decreases in both the incidence and years lived with disability rates among children and adolescents, especially in the 15-18 years age group, males, and most high-income regions. Notably, the incidence and years lived with disability rates were significantly decreased in middle and high-middle socio-demographic index regions but were increased in low and low-middle socio-demographic index regions.

CONCLUSIONS

Despite the remarkable progress between 1990 and 2019 in reducing the global burden of intraocular foreign bodies, there has been an increase in the number of cases, with substantial disparity across age groups, sexes, regions, and countries. Our results could inform more effective strategies for reducing the burden among children and adolescents.

Short-Term Effects: Elemental and Morphological Assessment of Aerosols Over Old Delhi Region, India

This study presents morphological and elemental characteristics of aerosols for the duration January-June, 2021, using Scanning Electron Microscope coupled with Energy Dispersive X-Ray (SEM–EDX). The results revealed that there were numerous spherical particles (D α ≤ 2.5 µm) but did not produced the expected EDX-spectra for elemental constituents. Limited deposited particles were observed which showed definite elemental constitutions. The results show that Cl, S, Al, Ca, K, Fe, Zn, Na, Mg, N, Tb, Ti, Ni, F, Cd, Cu, Mn, P and Cr were the overall determined elements, out of which Cl, S, Al, Ca, K, Fe, Zn, Na and Mg were the major constituents. Variation in particles’ shapes whether definite or irregular, columnar or spherical, flaky or aggregate or crystal-accumulation were attained on the basis of the major constituting element, majorly Ca-rich, S-rich, Cl-rich and Fe-rich. Interestingly, the physical characteristics of the particles varied with variation in elemental composition. All these indicate that there were specific sources contributing toward distinct particle-morphs. Ti, Tb and Cd need more analytical studies for their percent contribution. S, Cl and K contributed the most to the elemental composition as revealed by elemental relative proportion. Atomic weight percent curves for elements were slightly scattered during May. These probably played important role in defining the diversity indices, which was highest for April (2.17 ± 0.12). Particles containing six (P 6) to nine (P 9) elements dominated in this study, and particles containing seven elements (P 7) were generally observed.

On the techniques and standards of particulate matter sampling

Air pollution and its limits are regulated by the environmental protection agency of an individual country according to their National Ambient Air Quality Standards (NAAQS). Particulate matter (e.g., TSP, PM₁₀, and PM_2.5) is one of the important criteria pollutants of NAAQS. Their measurement methods are specified in NAAQS, and detailed technical descriptions are given in standards. This review focuses on the sampling and analysis techniques and methods in the context of PM samplers' design mentioned in countries specific PM measuring standards (e.g., EPA Part 50, CEN 12341, IS 5182(23), etc.) and their comparison wherever is necessary. It discusses, different designs of PM samplers mentioned in standards and its important components, e.g., size fractionators cutoff efficiency, PM sampler head design, flow measurement, and calibration, and also addresses the important issues that are the limitation of present standards. Our review reveals that most of the country-specific standards show common practice in measuring PM_2.5 using WINS impactor and VSCC cyclone as mentioned in EPA Part 50, except European Union (EU) standards, which has different design and parameters. For PM₁₀ measurement, sampler design is different in EU and Indian standards than that of U.S. EPA and other countries' standards, which is discussed in length here. All standards lack in pointing some inherent problems like change in D₅₀ cutoff of size fractionator of sampler under a high particle mass loading condition, which is common in countries like China and India. Other important issues where most of the standards lack include PM head design and specification, a key component of PM sampler on which the mass measurement results are largely dependent.Implications: The review paper discusses the air quality standards compliances of different countries and their comparisons. It focuses on the sampling and analysis techniques in context of PM samplers' design mentioned in countries specific PM measuring standards, and also addresses the important issues that are not mentioned in standards. Therefore, the discussions and findings of the review may be very useful while revising the existing air quality standards of different countries and to fill the research gap in this domain. Further, we have discussed several technical issues described in standards related to PM sampling which may be very helpful for PM sampler designing or modification in current designs as per the prevailing ambient conditions of a country.

Elucidating the responses of highly time-resolved PM2.5 related elements to extreme emission reductions

China's unprecedented lockdown to contain the spread of the novel coronavirus disease (COVID-19) in early 2020, provided a tragic natural experiment to investigate the responses of atmospheric pollution to emission reduction at regional scale. Primarily driven by primary emissions, particulate trace elements is vitally important due to their disproportionally adverse impacts on human health and ecosystem. Here 14 trace elements in PM_2.5 were selected for continuous measurement hourly in urban representative site of Shanghai, for three different phases: pre-control period (1-23 January 2020), control period (24 January-10 February 2020; overlapped with Chinese Lunar New Year holiday) and post control period (11-26 February 2020) the city's lockdown measures. The results show that all meteorological parameters (including temperature, RH, mixing layer height et al.) were generally consistent among different periods. Throughout the study period, the concentrations of most species displayed a "V-shaped" trend, suggesting significant effects by the restriction measures imposed during the lockdown period. While this is not the case for species like K, Cu and Ba, indicating their unusual origins. As a case study, the geographical origins of Cu were explored. Seven major sources, i.e., Vehicle-related emission (including road dust; indicative of Ca, Fe, Ba, Mn, Zn, Cu; accounting for 30.1%), shipping (Ni; 5.0%), coal combustion (As, Pb; 4.2%), Se and Cr industry (24.9%), nonferrous metal smelting (Au, Hg; 7.5%) and fireworks burning (K, Cu, Ba; 28.3%) were successfully pinpointed based on positive matrix factorization (PMF) analysis. Our source apportionment results also highlight fireworks burning was one of the dominant source of trace elements during the Chinese Lunar New Year holiday. It is worth noting that 56% of the total mass vehicular emissions are affiliated with non-exhaust sources (tire wear, brake wear, and road surface abrasion).

Thermite reaction driven pyrotechnic formulation with promising functional performance and reduced emissions

Green pyrotechnics/firecrackers reported herein are driven by thermite reactions for self-contained and self-sustained exothermic chemical reactions to make heat and sound by the usage of minimal fuel (aluminum), oxidizer (potassium nitrate), and Sulfur. These firecrackers have the potential for generating less emissions (70%) compared to commercial firecracker-based counterparts due to the presence of additives and are therefore designated as "Green firecrackers" or reduced emissions firecrackers. The functional performance and long-term stability of the composition was investigated through sound measurement and different tests, including ageing, thermal stability, and moisture test. The thermodynamics of the facilitated thermite reaction was cross-checked with experimental and theoretical methods. Prevalent mechanism for a substantial reduction in emissions to the tune of about 70% has been discussed. Cost of the green firecrackers is at par with the commercial firecrackers as cost of raw materials being used to prepare the formulation is comparable to the relatively toxic oxidizer substituted. "Green firecrackers" developed and reported here are environmentally benign in nature with higher business potential as far as a green chemistry-based sustainable solution for the society is required.

Air pollution in five Indian megacities during the Christmas and New Year celebration amidst COVID-19 pandemic

Urban air quality and COVID-19 have been considered significant issues worldwide in the last few years. The current study highlighted the variation in air pollutants (i.e., PM_2.5, PM₁₀, NO₂, and SO₂) profile between Christmas and new year celebrations in 2019, 2020, and 2021. It can be seen that the concentration of selected air pollutants shows a substantially higher concentration in celebration periods in all reported years. The results indicate that air pollutants values are always higher than permissible limits. This observation indicates that people gather and reunite during Christmas and new year celebrations than the preceding years (2020 and 2021) amidst the pandemic. In the pandemic year, a higher margin enhanced the transportation and firework-induced air pollutant load in urban city Jodhpur, Rajasthan. In all states, a significant tendency was observed to retain the concentration profile of air pollutants in baseline concentration for almost more than one week after the celebration. This study addresses the pandemic situation, but it also dealt with the air pollutant parameter that brings down the sustainable quality of the environment due to the high usage of private vehicles, and crackers. In addition, a study on COVID-19 (cases and death rate) indicates a clear picture of the increasing trend after the event in probably all states. Thus, this approach suggested that stringent law enforcement is needed to ameliorate gatherings/reunions and pollution levels due to such events.

How human mega-events influence urban airborne PM2.5 pollution: A systematic review and meta-analysis

Air pollution caused by PM_2.5 particles is a critical issue for public health that adversely affects people living in urban cities. Short-term Mega-events such as international meetings, sports tournaments, and traditional festivals can profoundly influence the local air quality. However, the extent of these influences and their role in improving or deteriorating the local air quality is still unclear. By collecting relative research from 75 publications based on more than 37 cities worldwide, we conducted a systematic review and meta-analysis. We calculated the log response ratio (RR) of the treatment (during) and control periods (before and after) of the Mega-events. The short-term policy control measures enacted during the Mega-Events consisting of meetings caused a significant decline (by -44.06%) in the ambient PM_2.5 concentration. The mean daily PM_2.5 concentration reduced from more than 100.00 μg/m³ before the events to 60.39 μg/m³, which is below the WHO (World Health Organization) interim target - 1 (75 μg/m³). On the contrary, setting off fireworks during the festival increased the ambient PM_2.5 concentrations by 89.57% on average, with a mean daily value of 254.22 μg/m³. The variations in the effects of all event types on the air quality were primarily influenced by the background PM_2.5 concentrations, with a negative correlation throughout. Moreover, the impact of events with policy control measures was also influenced by the year of the event, level of control, and location (suburban/urban) of the monitoring sites. Our findings provide evidence of the potential of human intervention on PM_2.5 pollution reduction. We further highlight the crucial role of background pollution level in implementing policies during the Mega-events, which can benefit the environmental governance of developing countries.

Toxic metals in outdoor/indoor airborne PM2.5 in port city of Northern, China: Characteristics, sources, and personal exposure risk assessment

Outdoor and indoor PM_2.5 samples were simultaneously collected over four seasons (2017-2018) in Caofeidian, China, and analyzed for 15 elements to investigate the characteristics, sources, and health risks of PM_2.5-bound metals. Source-specific PM_2.5-bound metals were analyzed using positive matrix factorization, combined with the conditional probability function and potential source contribution function model. The health risks were evaluated using the health risk assessment model, which included the exposure parameters of indoor and outdoor activities of Chinese residents. The annual median of PM_2.5 concentrations (89.68 μg/m³) and total metals (2.67 μg/m³) from the outdoor samples significantly surpassed that of the indoor samples (51.56 μg/m³) and total metals (1.51 μg/m³) (P < 0.05). In addition, the indoor/outdoor concentration ratios indicated that most indoor metals mainly originated from outdoor emission sources. In the annual analysis of PM_2.5-bound metal sources, this study identified five metal sources: coal combustion, resuspended dust, traffic emissions, fuel combustion sources, and industrial sources, among which industry sources (36.6%) contributed the most. The non-carcinogenic risks of metals for adults (2.81) and children (2.80) all exceed the acceptable non-carcinogenic risk level (1). The non-carcinogenic risk of Mn (1.46 for children, 1.48 for adults) was a key factor in the total non-carcinogenic risk. The total carcinogenic risk of metals for children (3.75 × 10^-5) was above the acceptable level (1.0 × 10^-6) but within the tolerant limit (1.0 × 10^-4), and that for adults (1.48 × 10^-4) was above the tolerant limit. The lifetime carcinogenic risk of Cr⁶⁺ had the highest proportion of the total carcinogenic risk for children (87.5%) and adults (87.8%). Our results revealed that both adults and children suffered carcinogenic and non-carcinogenic risks from the PM_2.5-bound metals in Caofeidian. The corresponding emission control measures of metals in atmosphere should be considered.

The contribution of commercial fireworks to both local and personal air quality in Auckland, New Zealand

Firework displays produce large amounts of particulate matter (PM), contributing to poor air quality in local areas. Since short-term exposure to particulate matter correlates with increased mortality risks, these celebrations may impact both human health and the environment. Little is known about the particulate matter produced from recreational fireworks, as most studies have focused on professional large-scale events. In New Zealand, it is common for consumer fireworks to be ignited within residential areas during the Guy Fawkes celebration around 5 November. To better understand the contribution of individual fireworks on local air quality, ambient PM₁₀ sampling was conducted in the 10 days surrounding Guy Fawkes Day in Auckland, New Zealand. These data were supplemented with measurements of firework emissions from 11 different individual products, including smoke bombs, sparklers, and Roman candles. Filter sampling results indicated that personal fireworks can contribute to ground level ambient air quality during celebrations, increasing ambient PM₁₀ concentrations by 21.6 μg m^-3 over a 12-h sampling period. The use of personal fireworks can expose consumers to PM₁₀ concentrations much higher, up to 9.51 mg m^-3 from individual sparkler use under worst-case scenario assumptions. The inhalation of sparkler emissions for just 8 min can lead to an exposure to PM₁₀ mass greater than that from daily recommended limits (50 μg m^-3 exposure over 24 h). X-ray fluorescence (XRF) analysis indicated that potassium (K) and strontium (Sr) can be used as tracers for local firework use and that arsenic (As) may be an important contaminant during Guy Fawkes celebrations. The PM from personal fireworks contained large amounts of chlorine (Cl), which may be indicative of perchlorate oxidizers. In addition, lead (Pb) was observed in the PM generated from two of the colored sparklers, which were marketed as "safer" alternatives to more explosive firework products.

Levels and sources of hourly PM2.5-related elements during the control period of the COVID-19 pandemic at a rural site between Beijing and Tianjin

To control the spread of the novel coronavirus disease 2019 (COVID-19) in China, many anthropogenic activities were reduced and even closed on the national scale. To study the impact of this reduction and closing down, hourly concentrations of PM2.5-related elements were measured at a rural site before (12-25 January 2020), during (26 January-9 February 2020) and after (22 March-2 April 2020) the control period when all people remained socially isolated in their homes and could not return to economic zones for work. Nine major sources were identified by the positive matrix factorization model, including fireworks burning, coal combustion, vehicle emissions, dust, Cr industry, oil combustion, Se industry, Zn smelter, and iron and steel industry. Before the control period, K, Fe, Ca, Zn, Ba and Cu were the main elements, and fireworks burning, Zn smelter and vehicle emissions provided the highest contributions to the total element mass with 55%, 12.1% and 10.3%, respectively. During the control period, K, Fe, Ba, Cu and Zn were the dominating elements, and fireworks burning and vehicle emissions contributed 55% and 27% of the total element mass. After the control period, Fe, K, Ca, Zn and Ba were the main elements, and dust and iron and steel industry were responsible for 56% and 21% of the total element mass. The increased contribution from vehicle emissions during the control period could be attributed to our sampling site being near a town hospital and the fact that the vehicle activities were not restricted. The source apportionment results were also related to air mass backward trajectories. The largest reductions of dust, coal combustion, and the industrial sources (Cr industry, Zn smelter, Se industry, iron and steel industry) were distinctly seen for northwest transport (Ulanqab) and were least significant for northeast transport (Tangshan and Tianjin).

Influence of fireworks emission on aerosol aging process at lower troposphere and associated health risks in an urban region of eastern central India

To study the influence of fireworks in atmospheric aerosols and their effect on health during the extreme firework days, fireworks tracer metals and carbonaceous species in size-distributed aerosols in the lower troposphere at Raipur in eastern central India were investigated during the 2018 Deepawali festival. Aerosol samples were collected, before Deepawali period (BDP, n = 5), during Deepawali period (DDP, n = 5) and after Deepawali period (ADP, n = 5). Bimodal size-distribution with intense fine mode peak was found for Na during DDP. Bimodal distribution with fine mode intense peak was found for K during DDP. The bimodal size distribution of K was found common for other events because of biomass burning emissions, whereas high intense peak during DDP indicated mixed sources from biomass burning and fireworks. During DDP, K and Ca were well correlated (r2 = 0.93) together. Strong metal-metal correlations were found between the following pairs, Zn-Fe, Cu-Fe and Cu-Ca, which indicated the similar firecrackers burning source. The atmospheric aging of aerosols was also found significantly high during fireworks days. Aging of aerosols were higher because of heterogeneous reactions of SO2 and NOx on aerosols directly emitted from fireworks. The observed high values of inhalation dose of elemental carbon during DDP period imposed higher risk of respiratory diseases. This study has provided carbonaceous fractions composition data as a tool to detect the aging processes of fireworks in ultra-fine, fine and coarse mode particles during the extreme firework days. Inhalation doses were calculated to establish potential influence on human health.

Chemical fingerprint and source apportionment of PM2.5 in highly polluted events of southern Taiwan

To investigate the spatial distribution and diurnal variation of the chemical composition of PM_2.5 pollution in an industrial city of southern Taiwan, 12-h PM_2.5 was diurnally continuously collected simultaneously at the Kaoping Air Quality Zone (KAQZ) during one highly PM_2.5-polluted episode. Water-soluble ions, metallic elements, carbonaceous contents, dicarboxylic acids, and anhydrosugars were analyzed to characterize the chemical fingerprint of PM_2.5. Backward trajectory simulation and chemical mass balance (CMB) receptor modeling were applied to identify the potential sources of PM_2.5 and their contributions. It showed that Chaozhou (rural area) accompanying the highest SORs and NORs suffered from the most severe PM_2.5 pollution during the episode. Sulfate (SO₄^2-) was probably formed by the atmospheric chemical reaction in the daytime, while NO₃^- processed at nighttime at the KAQZ. A homogeneous formation of NO₃^- occurred at Chaozhou. The concentrations of Zn, Pb, Fe, Cu, V, and Al, mainly emitted from anthropogenic sources, increased significantly at the KAQZ. The highest OC, SOC/OC, and DA/OCs at Daliao (industrial area) were attributed to the transformation of primary VOCs to secondary OC via photo-oxidation during the episode. Oxalic acid was mainly produced through photochemical reactions since a high correlation between oxalic acid and Ca²⁺ was observed at Nanzi (urban area) and Daliao during the episode. During the episode, PM_2.5 mostly originated from local primary or secondary aerosol than long-range overseas transport. The dominant source was anthropogenic emissions, accounting for 67.1% and 70.4% of PM_2.5 at Nanzi and Daliao, respectively. At Chaozhou, the contribution of anthropogenic emissions was the lowest (42.4%), but secondary aerosols had the highest contribution of 38.3% of PM_2.5 among the three areas during the episode.

Quantification of primary and secondary sources to PM2.5 using an improved source regional apportionment method in an industrial city, China

Identifying and quantifying the major sources of atmospheric particulate matter (PM) is essential for the development of pollution mitigation strategies to protect public health. However, urban PM is affected by local primary emissions, transport, and secondary formation; therefore, advanced methods are needed to elucidate the complex sources and transport patterns. Here, an improved source apportionment method was developed by incorporating the receptor model, Lagrangian simulation, and emissions inventories to quantify PM_2.5 sources for an industrial city in China. PM_2.5 data including ions, metals, organic carbon, and elemental carbon were obtained by analyzing 1 year of sampling results at urban and rural sites. This method identified coal combustion (30.64%), fugitive dust (13.25%), and vehicles (12.51%) as major primary sources. Secondary sources, including sulfate, nitrate, and secondary organic aerosols also contributed strongly (25.28%-30.76% in total) over urban and rural areas. Hebei Province was the major regional source contributor (43.05%-57.51%) except for fugitive dust, on which Inner Mongolia had a greater impact (43.51%). The megacities of Beijing and Tianjin exerted strong regional impacts on the secondary nitrate and secondary organic aerosols factors, contributing 11.32% and 15.65%, respectively. Pollution events were driven largely by secondary inorganic aerosols, highlighting the importance of reducing precursor emissions at the regional scale, particularly in the Beijing-Tianjin-Hebei region. Overall, our results demonstrate that this novel method offers good flexibility and efficiency for quantifying PM_2.5 sources and regional contributions, and that it can be extended to other cities.