Li Q
Introduction
Particulate matter (PM) has been identified as an important contributor of numerous adverse health effects, such as exacerbation of chronic respiratory and cardiovascular disease, decreased lung function, which are subject to the size of the PM, the encompassed chemical components and a variety of local conditions, including geology, meteorology, road surface, and traffic. Mostly, anthropogenic PM emissions in a country predominate over the PM resulted from natural activities, such as desert storm events, except Middle Eastern
countries, in which extreme weather conditions are often observed. Their anthropogenic emissions act as a higher enrichment factor for the total PM concentrations, especially for the PM-bound heavy metals, resulting from low utilization of public transport, aging vehicle fleet and the increasing number of personal vehicles [1]. Further, the high density urban development and rapid urbanization in the Middle East
enhance the PM exposure for the public. This commentary is intended to remark the PM-caused health effects in an urban area in the Middle. Eastern countries, and the challenges in the anthropogenic PM control measures, in terms of Air Quality Guideline (AQG) controls, public awareness improvement, and PM control strategies and abatement measures
PM Related Air Quality Guidelines
So far, a safe level of PM exposure has not been identified yet. Any AQG may not completely protect every individual from undergoing any possible PM-caused adverse health effects. The AQG recommended by World Health Organization (WHO) direct to achieve the lowest concentrations possible in the context of local constraints, capabilities, and public health priorities. The PM background concentrations in the Middle Eastern region are initially higher than in other countries for its natural weather conditions. However, their anthropogenic PM emissions are not really inferior to the emissions from the natural activities, especially traffic-related emissions. In Egypt, almost 36% of the ambient PM2.5 (76 µg/m3) is emitted by the one million vehicles in Cairo, which mostly are older ones with poor technical specifications [2]. More than one million vehicles are registered in Jordan, but 80% of them are running on the roadways in Amman. Another study found that in Jordan the PM10 and total suspended particulates are higher in the areas with heavy traffic [3].
Lack of a complete public transport system and high population density facilitate the PM-caused adverse health effects taking place in the public. Even so, only two countries (Iran and Israel) in the Middle East, have established some legislations, law, policies or acts specifically for ambient air quality. However, none of the Middle East countries have quantitative PM2.5 standards [4]. Some countries have published their specific national PM AQGs, whereas they are usually higher than the WHO’s AQGs. For instance, the AQG of 150 µg/m3 for 24 h exposure is recommended in Qatar, which is three times higher than 50 µg/m3 by WHO [5]. In spite of the less stringent AQG, the ambient PM concentrations are still far to meet their standards.
Qatar is deemed as one of the most polluted cities in the world for its higher PM2.5 concentrations. The WHO estimated that 75 µg/m3 of PM2.5 concentrations will increase the risk of short-term mortality about 5% over the AQG level [6].
Public Awareness of Exposure to PM Emissions
More importantly, most of the people in Middle Eastern countries are not aware of the health consequences from their daily exposure to anthropogenic PM emissions. Road traffic is the common source of the PM emissions among the countries, and ranks on the top of the sources in an urban area of the Middle East [2]. More than 800,000 people die from the PM2.5 exposures in cities around the world [7]. In Qatar, 31 out of every 100,000 people will die as a direct result of air pollution, which is higher than nearby United Arab Emirates, and much higher than most other countries, such as UK and USA [8]. Meanwhile, personal motor vehicle traffic has been kept expanding in the most Middle East countries, such as Lebanon, Qatar, Syria and United Arab Emirates, many of which just started to invest the public transport only
around a decade ago and their public networks are still limited [9]. Due to the rapid growth of vehicle traffic, frequent traffic congestion is inevitable. A significant amount of PM emissions is attributed to the traffic congestion and a large number of old vehicle combined with poor vehicle maintenance. During the congestion, commuters are exposing to the exhaust and non-exhaust PM emissions from the vehicle being stuck on roads. Personal PM exposure level could be varied with commuting
modes and cities with different traffic situations. In most cities located in Europe and Oceania, the PM exposure is higher in buses and cars than bicycles and walking [10,11]. Besides, Shaaban and Muley [12] found that pedestrians in Qatar walk more during the weekdays in the winter, and the weekend in the summer and spring. However, PM exhaust emissions from light-duty vehicles doubled for every 20�?? drop in ambient temperature [13].
The lack of awareness of personal exposure could be ascribed to a gap in the information regarding air quality monitoring, educational programs on health burden of ambient air pollution exposure to urban populations or under-appreciation of the potential solutions and measures addressed air pollution. Additionally, the impact of vehicle traffic on air quality and adverse health effects in the Middle Eastern countries are rarely investigated. Qatar is one of the few countries that have its own ground monitoring stations in the Middle East. However, only PM10 data have been collected [5] and plenty of construction projects have been active nationwide for the FIFA World Cup 2011. The construction activities raise another source of PM emissions, little quantitative data of which are available for the air quality deterioration and its associated health risk. Comparatively, the PM related air quality study in the Middle East countries fall far behind other developed countries.
PM Control Strategies and Abatement Measures
A review study concluded that insufficient effort is made to
implement convenient and practical alternative solutions for the ambient anthropogenic air pollution in the Middle East [2]. Considerable attention is suggested to pay to the future urban expansion, the absolute increase in motor vehicles and their poor technical specification, the extensive use of poor quality fuel and inappropriate combustion activities. In fact, more extensive PM control strategies and abatement measures have been carried out outside of the Middle Eastern. In many European countries, governments enforced stricter standards
and regulations for motor vehicles, such as substituting old vehicles by newer ones with more efficient engines and using cleaner fuels. They also financially promoted the use of public transport to reduce exhaust emissions from congestion. In the USA and China, financial subsidies have been implemented to encourage people to buy electrical vehicles. A voluntary national low emission vehicle program has been fulfilled to
mitigate the growth rate of vehicle mileage traveled in the USA. Over the recent decades, direct anthropogenic PM emissions decreased by 14% in the European Union [14]. Between 1990 and 2011, the reduction of anthropogenic PM emissions ranges from 40% to 53% [15]. These successful control strategies could be valuable references to the Middle
Eastern countries.
In the last few decades, most research and policy actions have extensively emphasized on exhaust emission reductions, whereas the PM2.5 emissions are predominately contributed by non-exhaust emissions. The PM emissions from wearing and tearing vehicle parts, such as brake, tire and clutch and resuspension of dust, are classified
as non-exhaust emissions. Evidence demonstrates that the nonexhaust emissions are consisted of coarse (PM2.5-10) and fine particle (PM2.5) [16]. Compared to exhaust emissions, the knowledge of nonexhaust emission
characteristics and patterns is relatively scarce [17]. Several
studies found that even with zero exhaust emissions (e.g. electrical vehicles), traffic will continue to emit fine and ultrafine particles, performing non-exhaust emissions [18,19]. By the end of the decade, almost 90% of the total emissions from road traffic will be derived from the non-exhaust sources [20]. Further, there is no specific regulation and effective estimate method to control and quantify the non-exhaust emissions, even in a developed country like the USA, which raise tremendous concern on the uncertainties of the PM-caused health effects [21]. Recent studies demonstrated that the non-exhaust emissions could be minimized by improving drivers’ driving behaviors, reducing congestion, and material improvement. Driving behaviors could be improved with the aid of an intelligent transportation system (ITS), such as V2V and V2I, to control traffic flow speed for minimal vehicle turbulence, and allow them to prevent hard brake events from
occurring [22]. During congestion, drivers are more likely to conduct a stop-and-go action during congestion, leading to higher abrasion PM emissions [23].
Besides, higher exhaust emissions are observed at the pavement with lower and higher roughness [24]. In this case, pavement material as well as type material could improve to mitigate material abrasion while braking or accelerating. However, it is worth noting that most of research in the PM controls and abatement measures are carried out in North America and Europe. The characteristics of the PM emissions in the Middle Eastern countries could be varied for their extreme meteorological conditions. The measures of ITS and material improvement ought to adapt to the regional conditions for effective PM abatement. In the USA, watering is commonly used to control PM emissions from scraper travel surfaces and other temporary travel routes at construction sites, which reduce an average of above 75% of PM10 emissions for 2 h [25]. There are more efficient methods, such as chemical dust suppressants, and building graveled and paved aprons, but more expensive. However, beside of these, few alternatives have been proposed to address the PM emissions from construction activities in the last decade.
Conclusion
Airborne PM emissions pose a threat of adverse health effects to the public, particularly in an urban area of the Middle East. In comparison to developed countries, the PM control strategies and abatement measures in the Middle Eastern countries fall far behind. It is suggested to pay attention to future urban expansion, the number motor vehicles and their technical specification, poor quality fuel and inappropriate combustion activities, for better air quality. In terms of PM abatement measures, researchers are confronting the uncertainties in monitoring and qualifying the non-exhaust from road traffic. The knowledge of non-exhaust PM emission characteristics and patterns is relatively scarce. Besides, a breakthrough is required for alternatives to effectively and economically reduce PM from construction activities.
Jean Moussa Kourouma
Abstract
Background
Heavy metal contamination of soils resulting from mining and smelting is causing major concern due to the potential risk involved. Heavy metals are generally defined as metals with noticeably high densities, atomic weights, or atomic numbers. The standards used, and whether metalloids are included, vary depending on the writer and context.[2] In metallurgy, as an instance, a heavy steel can be defined on the idea of density, whereas in physics the distinguishing criterion might be atomic number, while a chemist might probably be extra worried with chemical behaviour. More specific definitions have been posted, however none of those had been extensively conventional. The definitions surveyed in this text encompass as much as ninety six out of the 118 known chemical elements; most effective mercury, lead and bismuth meet all of them. Despite this loss of settlement, the time period (plural or singular) is broadly used in technology. A density of more than five g/cm3 is occasionally quoted as a usually used criterion and is used inside the frame of this text. With the increments in exceptional urbanization, industrialization, and human populace, soil substantial metal contamination has been noteworthy in the course of recent decades as a result of the poisonousness and undegradability of these poisons Many examinations have demonstrated that the collection of substantial metals in the dirt corrupts the nature of farmland, food yields, and people's living condition and undermines human wellbeing by means of the natural way of life or dermal contact. To reveal the potential pollution characteristics of heavy metals in the soils, the Geoaccumulation Index (Igeo), Enrichment Factor (EF) and Potential Ecological Risk Index (PERI), ordinary and indicator kriging (IK) interpolation methods were used to assess the corresponding ecological risk due to Cu, Cd, Zn, Pb and Ni contamination and depict the areas with high risk by estimating the probability of exceeding the FAO/WHO control standards. Metals were analyzed with Perkin Elmer Atomic Absorption Spectrophotometer.
Results
The Igeo indicated that the contamination degree ranged from uncontaminated to heavily contaminate in the areas closer to the polluting facility. . Residue can aggregate follow components in the earth. This investigation profiled the greatness of As, Ba, Cd, Co, Cu, Cr, Ni, Pb, Se, and Zn contamination in surface residue of the west bank of Peninsular Malaysia. Follow components were processed utilizing water regia and were broke down utilizing the inductively coupled plasma-mass spectrometry. The degree of natural contamination was assessed utilizing with the improvement factor (EF) and geoaccumulation file (Igeo). The EF ranges from deficient in the remote areas to significant enrichment in the soil collected in the vicinity of the polluting facility. The results of this examination will introduce a gauge information about soil quality status in rural soils, which might be useful in ensuring the food crop quality and eventually human health. The different CFs and records were utilized to various substantial metals to discover the level of contamination level and environmental dangers acted by overwhelming metals such like CF, EF, Igeo, expected natural hazard (RI), adjusted possible biological hazard (MRI), and so forth. (Kumar et al., 2018; Tian et al., 2017). These contamination records may delineate a subjective limit or focus on environmental hazard estimation of individual overwhelming metals.
Conclusion
The hotspot analysis and the spatial extent of metal contamination indicated several hotspots of Cu, Cd, Ni, Zn and Pb, which were strongly correlated to the locations of industrial plants and the irrigation systems of the study area. The normal convergences of Fe, Mn, Cu, and Zn were recorded lower than overall soils, Indian cutoff points for soil, Iran EPA rules, and Earth's outside layer. Heatmap and PCA indicated that characteristic sources have extraordinary effect on the dirt properties notwithstanding the anthropogenic sources. The consequences of CF and RI showed that overwhelming metals presented low tainting and natural dangers in the horticultural soils. The consequences of EF for Cu, Zn, and Mn uncovered exceptionally high enhancement, while Igeo estimations of Zn (92.6%) and Cu (66.1%) demonstrated high contamination, and all estimations of Igeo for Mn presented extraordinary contamination in horticultural soil tests of examined zone. The mEr esteems for Zn and Mn indicated that 69.1% and 48.5% farming soil tests demonstrated mEr values >320 and presented high biological dangers, while mEr estimations of Cu for all the examples demonstrated high environmental hazard. The aftereffects of geostatistcal examination uncovered that spatial conveyance guides of Zn for EF, Igeo, and MRI were disseminated more in Central areas, while spatial appropriation of Cu and Mn for these files was more in South and Northeastern districts of the contemplated territory. Further investigations are expected to comprehend the sources that are answerable for conveyance of substantial metals.Thus, government and mining companies should take actions to strengthen the environmental monitoring system the ecological restoration and the environmental protection around the major industrial sites of Copperbelt, Zambia. Keywords: Enrichment factor, Geo-Accumulation Index, Ecological Risk Index, contamination.
Castro e Silva D.M.
Bioaerosols are biological materials suspended in the air, and they also include fungi. The fungal genus Aspergillus is relevant in the respiratory infection of critical patients, and Aspergillus fumigatus is the most frequent species in the Metropolitan Region of São Paulo (MRSP), Brazil.
Aqsa Ramzan*
Water pollution with pathogenic microorganisms is one of the serious threats to human health, particularly in developing countries. The main objective of this article is to highlight microbial contamination of drinking water, the major factors responsible for microbial contamination, and the resulting health problems in Pakistan. Furthermore, this study will be helpful for researchers and administrative agencies to initiate relevant studies and develop new policies to protect further deterioration of water supply with pathogenic microbes and ensure clean and safe drinking water to the public in Pakistan. In Pakistan, water at the source, in the distribution network, and at the consumer tap is heavily polluted with coliforms and fecal coliforms all over the country.Improper disposal of industrial and municipal wastes is the most important factor responsible for water pollution in the country followed by crosscontamination due to old and leaking pipes. There is an urgent need for emergency steps to stop further deterioration of water quality and improve the existing water quality so as to protect the public from widespread waterborne diseases.
Youssef Hafez*
Although deficiencies in air dispersion Gaussian plume models have been well known, yet quantification of their negligence of some mechanisms like the longitudinal diffusion has not been yet made. This is done in this study using a three dimensional unsteady finite element model, Suite-3D (Solving Unsteady Incompressible Transport Equation in Three Dimensions, 3D). The model is developed to solve the advection-diffusion transport equation with decay and source terms. Suite-3D uses the standard Galerkin’s method without upwinding. Difference schemes are used (central, backward, forward) for the time integration. The elements are 8-node cubic brick elements (hexahedrons). Eight Gaussian quadrature points are used for the numerical integration of the element matrices. Suite-3D is validated against exact solutions of two problems; one has only advection and diffusion terms while the other has advection-diffusion-decay-source terms. The total percentage relative error for the first case was less than 0.61% while it reached 1.0% in the second case. The model is applied to study air pollution dispersion due to a point source. Special treatment is applied to allow comparing Suite-3D with the steady Gaussian
plume model. It is noted that neglecting the x-diffusion term in Gaussian plume model under calm wind conditions (velocity=0.2 m/s) results in discrepancies up to 81% at 180 m downstream of the source compared to prediction by the Gaussian plume model. In this zone Gaussian plume models can be considered to be not valid.
Abidemi Iromini, Atilola O
Head, trunk and tail of juvenile Clarias gariepinus exposed to pollutants; Detergent, Spent Oil and Detergent & Spent Oil in the volume 20 mg/L, 4 mg/L and 20 mg/L & 4 mg/L respectively, and were observed for the uptake of some selected heavy metals (Cu, Pb, Fe, Mn, and Zn). The study reveals the contamination of fish samples with heavy metals. The uptake of heavy metals in Fish samples were in the order of Fe> Zn> Cu> Mn> Pb in all pollutants, in the trend of Head>Trunk>Tail. The highest mean concentration was observed in Fe 48.33 ± 0.88(mg/kg) in the head of samples treated with detergent and Spent Oil, with uptake levels higher than the maximum permissible limits prescribed by WHO/ FAO. Whereas the concentration of heavy metals Cu, Pb, Mn and Zn were below the maximum permissible limits. The lowest mean concentration was observed in the tail.
Journal of Pollution received 64 citations as per Google Scholar report
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