Activity size distributions of radioactive airborne particles in an arid environment: a case study of Kuwait.

Atmospheric radioactive airborne released from several natural and artificial sources can travel for long distances and disperse in different directions. Both the physical and chemical characteristics of the atmospheric aerosols control this movement. The concentrations of 210Pb, 210Po, 7Be, 40K and 137Cs radionuclides in the ground surface air were determined in three particle sizes (2.4-10.2, 0.73-2.4 and less than 0.73 µm). High-volume air samples were collected from five different locations representing the five governorates of Kuwait using high-volume air samplers connected to a five-stage cascade impactor. The radioactivity concentrations of almost all fallout radionuclides were concentrated on the fine particle size fractions. The cosmogenic 7Be radioactivity level in all locations was relatively comparable and varied between 1.16 and 18.38 mBq/m3, with a geometric mean value of 6.80 mBq/m3. 137Cs was infrequently recorded with concentration varied between 4 and 14.3 µBq/m3. The geometric mean levels of the 210Po and 210Pb were 0.899 mBq/m3 and 1.03 mBq/m3, respectively, indicating that anthropogenic sources likely enrich 210Po. 40K was concentrated on large particle size fractions with a geometric mean value of 2.34 mBq/m3, reflecting the effects of the local dust sources. It was concluded that the radiological hazards due to airborne radioactive inhalation are low and can be negligible, where the annual estimated effective dose is about 64.0 µSv. The radioactive airborne measurements compose the base of estimating the aerosols residence time, resuspension rate of dust, soil redistribution and source apportionment, particularly the 210Pb and 210Po radionuclides.

Exposure levels of air pollution (PM2.5) and associated health risk in Kuwait.

It is well established that respiratory and cardiovascular mortality and morbidity rates are associated with poor air quality as measured by high concentrations of fine particulate matter such as PM2.5 parameters. Since such information is lacking for the State of Kuwait, this study examined the exposure levels of PM2.5 and the associated health risk as evaluated by five mortality measures embodied in ischemic heart disease, stroke, lung cancer, chronic obstructive pulmonary disease and acute lower respiratory infection as well as two morbidity outcomes related to both cardiovascular and respiratory diseases. The measurement models utilized in this investigation followed the WHO guidelines. Over a span of a four-year period (2014-2017), the annual PM2.5 concentration levels ranged from 38.0 µg/m3 to 75.2 µg/m3. In general, exposure levels tended to fluctuate throughout the day with the higher levels recorded during rush hours (early morning and early evening), weekends (particularly Saturdays), and summer (i.e., August and September). The highest number of excess cases and attributable proportions of premature mortalities were related to ischemic heart disease and stroke at 352 (95% CI 275-426) and 70.8% (95% CI 39.7-85.2), respectively. In general, respiratory diseases showed a higher number of excess cases and attributable proportions than cardiovascular diseases. Relative to other findings on the global stage, the results emanating from Kuwait are emerging on the higher side. The study outcomes suggest that control strategies are in dire need to bend the pollution levels in Kuwait.

Disability Adjusted Life Years (DALYs) in Terms of Years of Life Lost (YLL) Due to Premature Adult Mortalities and Postneonatal Infant Mortalities Attributed to PM2.5 and PM10 Exposures in Kuwait.

Ambient air pollution in terms of fine and coarse particulate matter (PM2.5 and PM10) has been shown to increase adult and infant mortalities. Most studies have estimated the risk of mortalities through attributable proportions and number of excess cases with no reference to the time lost due to premature mortalities. Disability adjusted life years (DALYs) are necessary to measure the health impact of Ambient particulate matter (PM) over time. In this study, we used life-tables for three years (2014⁻2016) to estimate the years of life lost (YLL), a main component of DALYs, for adult mortalities (age 30+ years) and postneonatal infant mortalities (age 28+ days⁻1 year) associated with PM2.5 exposure and PM10 exposure, respectively. The annual average of PM2.5 and PM10 concentrations were recorded as 87.9 µg/m³ and 167.5 µg/m³, which are 8 times greater than the World Health Organization (WHO) air quality guidelines of 10 µg/m³ and 20 µg/m³, respectively. Results indicated a total of 252.18 (95% CI: 170.69⁻322.92) YLL for all ages with an increase of 27,474.61 (95% CI: 18,483.02⁻35,370.58) YLL over 10 years. The expected life remaining (ELR) calculations showed that 30- and 65-year-old persons would gain 2.34 years and 1.93 years, respectively if the current PM2.5 exposure levels were reduced to the WHO interim targets (IT-1 = 35 µg/m³). Newborns and 1-year old children may live 79.81 and 78.94 years, respectively with an increase in average life expectancy of 2.65 years if the WHO PM10 interim targets were met (IT-1 = 70 µg/m³). Sensitivity analyses for YLL were carried out for the years 2015, 2025, and 2045 and showed that the years of life would increase significantly for age groups between 30 and 85. Life expectancy, especially for the elderly (≥60 years), would increase at higher rates if PM2.5 levels were reduced further. This study can be helpful for the assessment of poor air quality represented by PM2.5 and PM10 exposures in causing premature adult mortalities and postneonatal infant mortalities in developing countries with high ambient air pollution. Information in this article adds insights to the sustainable development goals (SDG 3.9.1 and 11.6.2) related to the reduction of mortality rates attributed to ambient air levels of coarse and fine particulate matter.

Source apportionment of airborne nanoparticles in a Middle Eastern city using positive matrix factorization.

Airborne nanoparticles have been studied worldwide, but little is known about their sources in the Middle East region, where hot, arid and dusty climatic conditions generally prevail. For the first time in Kuwait, we carried out size-resolved measurements of particle number distributions (PNDs) and concentrations (PNCs) in the 5-1000 nm size range. Measurements were made continuously for 31 days during the summer months of May and June 2013 using a fast-response differential mobility spectrometer (Cambustion DMS500) at a sampling rate of 10 Hz. Sources and their contributions were identified using the positive matrix factorization (PMF) approach that was applied to the PND data. Simultaneous measurements of gaseous pollutants (i.e., O3, NO, NOx, SO2 and CO), PM10, wind speed and direction were also carried out to aid the interpretation of the PMF results through the conditional probability function plots and Pearson product-moment correlations. Six major sources of PNCs were identified, contributing ∼46% (fresh traffic emissions), 27% (aged traffic emissions), 9% (industrial emissions), 9% (regional background), 6% (miscellaneous sources) and 3% (Arabian dust transport) of the total PNCs. The sources of nanoparticles and their PND profiles identified could serve as reference data to design more detailed field studies in the future and treat these sources in dispersion modelling and health impact assessment studies.

Number and size distribution of airborne nanoparticles during summertime in Kuwait: first observations from the Middle East.

We made fast response measurements of size-resolved particle number concentrations (PNCs) and distributions (PNDs) in the 5-1000 nm range close to a busy roadside, continuously for 31 days, in Kuwait. The aims were to understand their dispersion characteristics during summertime and dust events, and association with trace pollutants (NOx, O3, CO, SO2, and PM10) and meteorological parameters. PNCs were found up to ∼19-times higher (5.98 × 10(5) cm(-3)) than those typically found in European roadside environments. Size distributions exhibited over 90% of PNCs in ultrafine size range (<100 nm) and a negligible fraction over 300 nm. Peak PNDs appeared at ∼12 nm, showing an unusually large peak in nucleation mode. Diurnal variations of PNCs coincided with the cyclic variations in CO, NOx, and traffic volume during morning and evening rush hours. Despite high traffic volume, PNC peaks were missing during noon hours due to high ambient temperature (∼48 °C) that showed an inverse relationship with the PNCs. Principal Component Analysis revealed three probable sources in the area--local road traffic, fugitive dust, and refineries. Dust events, categorized by PM10 with over 1000 µg m(-3), decreased PNCs by ∼25% and increased their geometric mean diameters (GMDs) by ∼66% compared with nondust periods.