Role of air pollution on seasonal distribution of Covid-19: a case study in the west of Iran.

The seasonal distribution of SARS-CoV-2 might be affected by air pollution. To test the hypothesis, epidemic determinants, namely, shape, timing (Peak and Trough) and size (Peak to Trough Ratio and Excess Risk) of seasonal distribution of the outbreak were compared before and after adjusting for air pollutants in a distributed lag nonlinear model. We controlled for one-lagged outcome and meteorological parameters in the model. We also evaluated interaction effect between air pollutants and season using stratification method. The epidemic determinants were changed after adjusting for PM2.5 and O3 in the model, suggesting the existence of their association with the seasonal distribution of the outbreak. The Excess Risk of season (i.e., the proportion of confirmed Covid-19 cases that were attributed to season; AF) was increased as %4 (%95 CI - 29, 38) after adjusting for PM2.5. Adjusting for O3 in the model resulted in % 1 (%95 CI - 36, 34) decrease in the index. NO, NO2 and SO2 had no association with the seasonal distribution, though the interaction analysis revealed that association of NO2 and SO2 with Covid-19 confirmed cases were significantly higher in fall than winter and spring, respectively. Totally, PM2.5 has negatively associated with the seasonal distribution of the outbreak while O3 has positively associated in the region under study. Although some reasons such as wearing mask and oxidative effect might go before the negative and positive associations, but our results suggests that any association and causation between air pollution and Covid-19 should be carefully interpreted.

An environmentally extended global multi-regional input-output analysis of consumption-based and embodied import-based carbon emissions of Turkey.

Understanding the consumption-based accounting (CBA), production-based accounting (PBA), and emissions embodied in trade is an important prerequisite for designing climate mitigation policies. Environmentally extended input-output (EEIO) models have been developed to evaluate the linkages between economic activities and environmental impacts as well as the embodied emissions in goods and services that are traded between countries. In this study, an environmentally extended global multi-regional input-output (EE GMRIO) analysis is performed to calculate Turkey's CBA emissions and import-based embodied emissions for the year 2015 using the Eora26 database, which is a simplified version of the Eora database adapted to 26 economic sectors. The key sectors and sectoral carbon intensities of countries are determined in terms of embodied emissions in imports for household consumption. Our results indicate that Turkey was a net importer of greenhouse gas (GHG) emissions in 2015 and about 10% of total emissions of the final consumption in Turkey have occurred in other countries. The dominant contributing sectors to a nation's GHG emissions can be quite different for the CBA and PBA approaches and the efforts to reduce GHG emissions requires a holistic approach. Import-based household emissions are assessed in terms of countries, sector and GHG intensities. Our results indicate that Turkey was a net importer of GHG emissions in 2015 with its approximately 10% of the total and 7.7% of household final consumption emissions having occurred in other countries. This also suggests that imported goods and services for household consumption have been produced in those countries with relatively low emission intensities. Considering Turkey's emissions reduction targets, these results provide methodological benefits that will enhance national efforts by giving invaluable inputs about the emission intensity of imported and exported goods and better guidance to policy makers about future strategies for low-carbon manufacturing and shifting consumption patterns.

Assessment of the health risk related to exposure to ultrafine, fine, and total particulates and metals in a metal finishing plant.

The materials and byproducts of the processes used in the metal finishing industry are released as particle contaminants into the air in the workplace. The present study aimed to determine the concentrations and size distributions of these particles and of elements chromium, nickel, copper, manganese, cobalt, and lead (Cr, Ni, Cu, Mn, Co, and Pb, respectively) in a metal finishing industry and evaluate their potential health risks. Particles that are airborne from the dipping baths in the plant were sampled using a Sioutas cascade impactor at five different size fractions (PM>2.5, PM1.0-2.5, PM0.5-1.0, PM0.25-0.5, PM<0.25) and gravimetric analyses were conducted on the sampled filters. The GF-AAS 600 graphite atomic absorption spectrophotometer (PerkinElmer Corporation, Waltham, MA, USA) was used to analyze the elements and the method of USEPA was used to assess the health risk. The ratio of fine particles (PM2.5) to total suspended particles (TSPs) was 0.6. We observed that 50% of TSPs were composed of PM1.0 and that 68-88% of the metals were found in the fine particle fractions. Pb, Cr, and Mn were significantly positively correlated in the PM1.0 fraction, and the highest linear relationship was found between Pb and Cr (r = 0.85, p < 0.01). The total hazard quotient (HQ) for PM2.5 was 1.43, which is higher than the acceptable limit of 1.0. The excess lifetime cancer risk (ELCR) for hexavalent chromium (Cr[VI]) in PM2.5 was 6.09 × 10-5 for female workers and 6.54 × 10-5 for male workers, which are higher than the acceptable limit of 1.0 × 10-6, while total ELCRs for female and male workers were 6.21 × 10-5 and 6.21 × 10-5, respectively. The lifetime cancer risk associated with Cr(VI) in Cr electroplating plants should be taken into consideration as a significant health risk for the workers.

An ecological risk investigation of marine sediment from the northern Mediterranean coasts (Aegean Sea) using multiple methods of pollution determination.

The aim of this study is an assessment of metal pollution levels in Aegean Sea sediment. Sediment samples collected from 7 different locations (Yeniköy, Edremit, Ayvalik, Dikili, Aliaga, Hekimadasi, and Ildir) along the northern Mediterranean region of Turkey were investigated for 11 elements (Cu, Fe, Zn, V, Cd, Ni, As, Pb, Mn, Co, and Cr). Graphite furnace atomic absorption spectrophotometry (GFAAS) and flame atomic absorption spectrophotometry (FAAS) were used for elemental analysis. The findings were evaluated with sediment assessment methods by taking two different values as a reference and then investigating the adverse biological effects of elemental profiles on living organisms. Pb, Mn, As, Cd, and Cr concentrations were within a moderate to significant range in terms of contamination factor [Formula: see text]), albeit varying according to reference and location. The most problematic region and elements regarding the enrichment factor (EF) was Ayvalik and As, Ni, Cu, Pb, Co, and Cd. However, according to the EF, the anthropogenic effect was not at an alarming level. This was further supported by the results of the geoaccumulation index (Igeo). The findings of the modified degree of contamination (mC d ) and the pollution load index (PLI) suggested that the accumulation was greatest in Ayvalik, and the least in Hekimadasi and Ildir. The location with the highest elemental total toxic unit (ΣTU) was Edremit. The effect of the existing element profile on organisms was 21% in this location when the mean effect range-median quotient (m-ERM-q) was considered. As and Ni concentrations in all stations were found to be higher than threshold effect level (TEL) and Effect Range Low (ERL). Ni levels in Edremit exceeded the probable effect level (PEL) and Effect Range Median (ERM). Toxic unit (TU) values of these two elements in all stations ranged from 59.30 to 80.43%.

Mass size distribution and source identification of particulate matter metal components at four urban sites and a background site of Istanbul.

In this study, the size distribution characteristics and metal contents of particulate matter (PM) have been determined. In this scope, PM sampling has been done at five stations in Istanbul. PM filter samples were collected for eight different sizes using the Anderson cascade impactor. PM filters were decomposed and analyzed for 20 metals. The highest median concentration for Fe, Ca, K, and Mg, known as soil metals, were observed as follows: Fe and Ca were observed at Goztepe station (1.20 and 8.28 µg/m(3)), K was observed at Kilyos station (0.33 µg/m(3)), and Mg was observed at Avcilar station (0.37 µg/m(3)). The highest median concentrations for Zn, Cu, Pb, Ni, Cr, V, As, Se, Co, and Cd, known as anthropogenic metals, were observed at Avcilar, Goztepe, and Besiktas stations. Although the lowest metal concentrations was determined at Kilyos stations that was selected as the urban background. The enrichment factors (EFs) of most metals in the fine PM is higher than those in the coarse mode. According to the factor analyses, the most important emission source was observed to be industrial facilities at Avcilar; traffic at Besiktas; traffic and domestic heating at Goztepe; and domestic heating, sea salt aerosols, and ship traffic (in the Bosphorus Channel of Istanbul) at Rasathane.

Assessment of fine particulate matter and gaseous pollutants in workplace atmosphere of metallic industry.

In the present study, we measured the concentrations of fine particulate matter (PM(2.5)), carbon dioxide (CO(2)), carbon monoxide (CO) and volatile organic carbon (VOC) in the indoor air of the manufacturing department of a metal factory. The daily average PM(2.5) concentration ranged between 86.3 and 404.9 µg/m(3). The isolation of the manufacturing machines reduced. PM(2.5) concentration between 2.5 and 8.8 fold. At the seven measurement points, daily concentrations ranged from 576.7 to 623.4 ppm for CO(2), 0.8 to 15.8 ppm for CO, and 0 to 0.58 ppm for VOC, respectively.

Size distribution and seasonal variation of airborne particulate matter in five areas in Istanbul, Turkey.

GOAL, SCOPE, AND BACKGROUND: Many studies have focused on measuring fine and course particulate matter (PM) in urban and rural sites around the world. The aim of this research is to gain information on the size distribution of particles. The physical characteristics of PM in the urban air of Istanbul were determined. METHODS: PM sampling was carried out at five stations (Avcilar, Besiktas, Kilyos, Rasathane, and Göztepe) over a period of 2 years. PM filter samples were collected for eight different size ranges (<0.43, 0.43-1, 1-1.7, 1.7-2.6, 2.6-3.5, 3.5-5.2, 5.2-6.5, 6.5-8, and >8 µm) using a Cascade Impactor. The size distributions of the PM samples were determined. RESULTS AND DISCUSSION: The mean total PM concentrations were 48.6 ± 34.0, 34.8 ± 11.6, 28.6 ± 13.6, 21.5 ± 9.1, and 16.8 ± 5.1 µg/m(3) for the Göztepe, Besiktas, Avcilar, Rasathane, and Kilyos stations, respectively. The total PM concentrations were found to be 1.2-1.5 times higher in the fall and winter than in the spring and summer, except for at the station in Avcilar. The PM concentrations in Avcilar did not exhibit seasonal variations. This is thought to result from the intense industrial activity in the area. PM(2.6) (below 2.6 µm particles) comprised up to 62% of the total amount of PM in samples collected at the Göztepe, Besiktas, and Rasathane stations during the fall and winter. PM(1) was determined to be approximately 45% of the total, corresponding to 57% of the amount of PM(2.5). A multi-modal PM size distribution was observed. The lowest Mass Median Aerodynamic Diameter (MMAD) values observed in Avcilar, Besiktas, Rasathane, and Göztepe were 4.2, 3.9, 2.9, and 3.5 µm, respectively, and were observed during the season of active household heating. No difference was measured in the MMAD values (5.2 µm) between the seasons of heating and non-heating in Kilyos.