scholarly journals Characterization of PAHs Trapped in the Soot from the Combustion of Various Mediterranean Species

Atmosphere ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 965
Author(s):  
Valérie Leroy-Cancellieri ◽  
Dominique Cancellieri ◽  
Eric Leoni

Climate change causes more frequent and destructive wildfires even transforming them into megafire. Moreover, all biomass fires produce emissions of carbon compounds in the form of soot to the atmosphere with a significant impact on the environment and human health. Indeed, the soot is causing the formation of PAHs from (a) the high temperature thermal alteration of natural product precursors in the source organic matter and (b) the recombination of molecular fragments in the smoke. However, these molecules are known to have carcinogenic effects on human health. It is therefore interesting to quantify the 16 PAHs concentration extracted from soot emitted in open diffusion flame of biomass combustion. To achieve this objective, an analytical method developed for the study of kerosene combustion has been adapted for soot from biomass. This new method allowed to quantify the 16 PAHs defined as priority pollutants by the US EPA for their carcinogenic mutagenic effect and on human health.

2006 ◽  
Vol 25 (1) ◽  
pp. 29-43 ◽  
Author(s):  
P F Ricci ◽  
L A Cox ◽  
T R MacDonald

How can empirical evidence of adverse effects from exposure to noxious agents, which is often incomplete and uncertain, be used most appropriately to protect human health? We examine several important questions on the best uses of empirical evidence in regulatory risk management decision–making raised by the US Environmental Protection Agency (EPA)'s science–policy concerning uncertainty and variability in human health risk assessment. In our view, the US EPA (and other agencies that have adopted similar views of risk management) can often improve decision–making by decreasing reliance on default values and assumptions, particularly when causation is uncertain. This can be achieved by more fully exploiting decision–theoretic methods and criteria that explicitly account for uncertain, possibly conflicting scientific beliefs and that can be fully studied by advocates and adversaries of a policy choice, in administrative decision–making involving risk assessment. The substitution of decision–theoretic frameworks for default assumption–driven policies also allows stakeholder attitudes toward risk to be incorporated into policy debates, so that the public and risk managers can more explicitly identify the roles of risk–aversion or other attitudes toward risk and uncertainty in policy recommendations. Decision theory provides a sound scientific way explicitly to account for new knowledge and its effects on eventual policy choices. Although these improvements can complicate regulatory analyses, simplifying default assumptions can create substantial costs to society and can prematurely cut off consideration of new scientific insights (e.g., possible beneficial health effects from exposure to sufficiently low ‘hormetic’ doses of some agents). In many cases, the administrative burden of applying decision–analytic methods is likely to be more than offset by improved effectiveness of regulations in achieving desired goals. Because many foreign jurisdictions adopt US EPA reasoning and methods of risk analysis, it may be especially valuable to incorporate decision–theoretic principles that transcend local differences among jurisdictions.


2011 ◽  
Vol 4 (6) ◽  
pp. 7559-7595
Author(s):  
E. J. Alston ◽  
I. N. Sokolik ◽  
O. V. Kalashnikova

Abstract. This study examines how aerosols measured from the ground and space over the US Southeast change temporally over a regional scale during the past decade. PM2.5 data consist of two datasets that represent the measurements that are used for regulatory purposes by the US EPA and continuous measurements used for quickly disseminating air quality information. AOD data comes from three NASA sensors: the MODIS sensors onboard Terra and Aqua satellites and the MISR sensor onboard the Terra satellite. We analyze all available data over the state of Georgia from 2000–2009 of both types of aerosol data. The analysis reveals that during the summer the large metropolitan area of Atlanta has average PM2.5 concentrations that are 50% more than the remainder of the state. Strong seasonality is detected in both the AOD and PM2.5 datasets; as evidenced by a threefold increase of AOD from mean winter values to mean summer values, and the increase in PM2.5 concentrations is almost twofold from over the same period. Additionally, there is good agreement between MODIS and MISR onboard the Terra satellite during the spring and summer having correlation coefficients of 0.64 and 0.71, respectively. Monthly anomalies were used to determine the presence of a trend in all considered aerosol datasets. We found negative linear trends in both the monthly AOD anomalies from MODIS onboard Terra and the PM2.5 datasets, which are statistically significant for α = 0.05. Decreasing trends were also found for MISR onboard Terra and MODIS onboard Aqua, but those trends were not statistically significant.


2002 ◽  
Vol 757 ◽  
Author(s):  
James L. Jerden ◽  
A. K. Sinha

ABSTRACTThe unmined Coles Hill U deposit in the Virginia Piedmont represents a unique natural laboratory for studying the long-term containment of U by phosphate minerals. The primary ore assemblage consists of coffinite and apatite and is hosted in foliated granite. Geochemical and mineralogical studies of the weathered bedrock and soils developed over the primary ore body indicate that U transport is inhibited by the precipitation of meta-autunite group minerals. The lower part of the profile, which consists of ground water saturated saprolite, contains 1400 mg/kg U (in the solid). This concentration is 1.5 times greater than the mean ore grade of the deposit, indicating that the saprolites are enriched in U relative to the underlying primary ore. Uranium within the saprolite is dominantly associated with 10 to 500 μm long, tabular crystals of (Ba, Ca, Sr) meta-autunite. Ground waters from this zone contain less than 14 μg/L dissolved U suggesting that the U(VI) phosphate minerals present are capable of controlling dissolved U concentrations at values lower than the US-EPA maximum contaminant level (30 μg/L). Mineralogical characterization of the unsaturated soil horizons indicate that geochemical conditions in these zones are not conducive to U stabilization by meta-autunite mineralization. In the vadose zone U is primarily associated with Al phosphate (crandallite) and with P adsorbed or coprecipitated with iron oxide mineral coatings. Geochemical gradients suggest that significant amounts of U have been leached from the vadose zone by infiltrating fluids and reprecipitated below the water table, where the activity ratio of dissolved phosphate to carbonate increases. Based on regional weathering rates, the processes responsible for stabilization of U within the Coles Hill system are estimated to have been active for hundreds of thousands of years.


2020 ◽  
Vol 4 (3) ◽  
pp. 481-488
Author(s):  
Mukhtar Balarabe ◽  
Bello Saadu

To improve our understanding of the impact of desert dust on human health, there is need to constantly monitor and examined the dust related phenomena. Therefore, twenty 20 year’s (1998–2018) data of visibility for Ilorin Nigeria were used to estimate the concentrations of the Total Suspended Particles (TSP) and Particulate Matter PM10 as usually used to monitor air quality on international level. The results established the threshold for daily concentration of TSP (254) and PM10 (186) μgm−3 at the study sites. It also identified months (November-March) of the following year with the greatest number of days having low air quality (high concentration of TSP and PM10). These months are responsible for 47% of the annual air pollution and number of days above the US EPA-NAAQSTSP, US EPA-NAAQS PM10 as well as the 24-hour EU-LVAQ regulations, respectively. Furthermore, some considerable numbers of days were found to experienced hazardous atmospheric condition for the total number of days, Harmattan and summer respectively. The concentrations of PM10 (0-54 μgm−3) showed absence of good air quality throughout the period of study. Even though, there were significant number of days associated with moderate air quality most of which occurs during summer. Consequence of which can lead to increased respiratory symptoms and aggravation of lung diseases. It was also observed that, the concentrations of TSP and PM10 start of build up in the atmosphere by October, reaching peak in December and January before it decline by April and remain low with almost uniform values until September.


2012 ◽  
Vol 5 (7) ◽  
pp. 1667-1682 ◽  
Author(s):  
E. J. Alston ◽  
I. N. Sokolik ◽  
O. V. Kalashnikova

Abstract. This study examines how aerosols measured from the ground and space over the US Southeast change temporally over a regional scale during the past decade. PM2.5 (particulate matter with aerodynamic diameter >2.5 micrometers) data consist of two datasets that represent the measurements that are used for regulatory purposes by the US EPA (Environmental Protection Agency) and continuous measurements used for quickly disseminating air quality information. AOD (aerosol optical depth) data come from three NASA sensors: the MODIS sensors onboard Terra and Aqua satellites and the MISR sensor onboard the Terra satellite. We analyze all available data over the state of Georgia from 2000–2009 of both types of aerosol data. The analysis reveals that during the summer the large metropolitan area of Atlanta has average PM2.5 concentrations that are 50% more than the remainder of the state. Strong seasonality is detected in both the AOD and PM2.5 datasets, as evidenced by a threefold increase of AOD from mean winter values to mean summer values, and the increase in PM2.5 concentrations is almost twofold over the same period. Additionally, there is agreement between MODIS and MISR onboard the Terra satellite during the spring and summer, having correlation coefficients of 0.64 and 0.71, respectively. Monthly anomalies were used to determine the presence of a trend in all considered aerosol datasets. We found negative linear trends for both the monthly AOD anomalies from MODIS onboard Terra and the PM2.5 datasets, which are statistically significant. Decreasing trends were also found for MISR onboard Terra and MODIS onboard Aqua, but those trends were not statistically significant. The observed decrease in AOD and PM2.5 concentrations may be indicative of the brightening over the study region during the past decade.


2019 ◽  
Author(s):  
Chem Int

Liquid effluents discharged by hospitals may contain chemical and biological contaminants whose main source is the different substances used for the treatment of patients. This type of rejection can present a sanitary potentially dangerous risk for human health and can provoke a strong degradation of diverse environmental compartments mainly water and soils. The present study focuses on the quality of the liquid effluents of Hassani Abdelkader’s hospital of Sidi Bel-Abbes (West of Algeria). The results reveal a significant chemical pollution (COD: 879 mgO2/L, BOD5: 850 mgO2/L, NH4+ : 47.9 mg/l, NO2- : 4.2 mg/l, NO3- : 56.8 mg/l with respect to WHO standard of 90 mgO2/L, 30 mgO2/L, 0.5 mg/l, 1 mg/l and 1 mg/l respectively). However, these effluents are biodegradable since the ratio COD/BOD5 do not exceeded the value of 2 in almost all samples. The presence of pathogen germs is put into evidence such as pseudomonas, the clostridium, the staphylococcus, the fecal coliforms and fecal streptococcus. These results show that the direct discharge of these effluents constitutes a major threat to human health and the environment.


2021 ◽  
Vol 11 (5) ◽  
pp. 2388
Author(s):  
Yongku Kim ◽  
Jeongjin Lee

In environmental studies, it is important to assess how regulatory standards for air pollutants affect public health. High ozone levels contribute to harmful air pollutants. The EPA regulates ozone levels by setting ozone standards to protect public health. It is thus crucial to assess how various regulatory ozone standards affect non-accidental mortality related to respiratory deaths during the ozone season. The original rollback approach provides an adjusted ozone process under a new regulation scenario in a deterministic fashion. Herein, we consider a statistical rollback approach to allow for uncertainty in the rollback procedure by adopting the quantile matching method so that it provides flexible rollback sets. Hierarchical Bayesian models are used to predict the potential effects of different ozone standards on human health. We apply the method to epidemiologic data.


Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3079
Author(s):  
Beata Jaworska ◽  
Dominika Stańczak ◽  
Joanna Tarańska ◽  
Jerzy Jaworski

The generation of energy for the needs of the population is currently a problem. In consideration of that, the biomass combustion process has started to be implemented as a new source of energy. The dynamic increase in the use of biomass for energy generation also resulted in the formation of waste in the form of fly ash. This paper presents an efficient way to manage this troublesome material in the polymer–cement composites (PCC), which have investigated to a lesser extent. The research outlined in this article consists of the characterization of biomass fly ash (BFA) as well as PCC containing this waste. The characteristics of PCC with BFA after 3, 7, 14, and 28 days of curing were analyzed. Our main findings are that biomass fly ash is suitable as a mineral additive in polymer–cement composites. The most interesting result is that the addition of biomass fly ash did not affect the rheological properties of the polymer–cement mortars, but it especially influenced its compressive strength. Most importantly, our findings can help prevent this byproduct from being placed in landfills, prevent the mining of new raw materials, and promote the manufacture of durable building materials.


2012 ◽  
Vol 620 ◽  
pp. 469-473 ◽  
Author(s):  
Norhashimah Ramli ◽  
Mohammad Hafizuddin Haji Jumali ◽  
Wan Safizah Wan Salim

Dredging along Kuala Perlis Jetty results in huge amount of marine sediments which has thrown considerable challenge for disposal. This research was conducted to characterize dredged marine sediment which was collected at Kuala Perlis Jetty as potential raw material for brick production. Three different characterizations were performed namely XRF, XRD and FTIR. XRF analysis showed the presence of SiO2 and Al2O3 as major quantities. Low concentration of heavy metals namely As, Cr, Cu, Pb, Ni and Zn presence in the sediment comply the US EPA guideline for brick production. XRD analysis indicated the presence of quartz as primary mineral while kaolinite and illite also present as secondary and ternary phases. FTIR analysis identified various form of minerals presence in the samples which strongly supported XRD results.


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