Association between Chronic Exposure to Ambient Air Pollutants, Demography, Vaccination Level, and the Spread of COVID-19 during 2021 Delta Variant Morbidity Wave

Studies conducted in the early COVID-19 pandemic stages showed positive associations between chronic exposure to ambient air pollution and COVID-19 morbidity. Here, we examined the associations between populations' chronic exposure to air pollutants (NO2, CO, PM10, PM2.5, and SO2), demographics, and vaccination rates, to COVID-19 morbidity rates in 280 Israeli municipalities during the Delta-variant-dominated morbidity wave of summer 2021. We found that COVID-19 morbidity was positively associated with chronic exposure to air pollutants, the municipality's population density, total population size, and the rate of elderly people. Multivariate linear regression models showed similar trends: positive associations between COVID-19 rates and density, ratio of elderly people, and most air pollutants, and a non-significant link to COVID-19 vaccine second dose ratio. Our results emphasized the effects of chronic air pollution exposure on the spread of the pandemic and strengthen the urgent need for uncompromising policy for a dramatic reduction in air pollution. They also highlighted the vulnerable populations (elderly, densely populated municipalities) during the Delta morbidity wave. These findings could assist policy makers to better inform the public and manage health policies in future COVID-19 waves, hopefully leading to a reduced impact on health.

Results of the national biomonitoring program show persistent iodine deficiency in Israel.

BACKGROUND: Adequate iodine intake is essential for human health, for normal thyroid function, and for attainment of full intellectual potential in children. In light of Israel's lack of a mandatory salt fortification policy, heavy reliance on desalination and low iodine intake from dairy products and seafood, there is concern in Israel that the population is iodine deficient. Indeed, the first Israeli National Iodine Survey in 2016 found a median urinary iodine concentration (UIC) of 83 µg/L among school age children, falling below the WHO's adequacy range of 100-299 µg/L for children. METHODS: In the framework of the National Human Biomonitoring Program in Israel, spot urine samples and questionnaire data were collected from 166 healthy children aged 4-12 years in 2020-2021. Urinary iodine concentrations were measured at the Ministry of Health National Biomonitoring Laboratory, using mass spectrometry. An international comparison of median urinary iodine concentrations (UIC) was performed taking into consideration the levels of desalinated water per capita, and fortification policies. RESULTS: The overall median (interquartile range [IQR]) UIC was 80.1 µg/L (44.7-130.8 µg/L) indicating that the population's iodine status has not improved in the five years that have passed since inadequacy was first identified. When comparing 13 countries with population size above 150,000, whose desalinated water per capita was at least 1 m3, Israel and Lebanon were the only countries with median UIC below the WHO adequacy range. CONCLUSIONS: There is an urgent need for mandatory salt fortification in Israel. Based on our international comparison, we conclude that the potential impact of desalination on iodine intake can be compensated for using the implementation of salt fortification policy. This study highlights the critical need for public health surveillance of nutritional and environmental exposures using human biomonitoring, with emphasis on vulnerable populations such as pregnant women and children.

Effects of chronic exposure to ambient air pollutants, demographic, and socioeconomic factors on COVID-19 morbidity: The Israeli case study.

BACKGROUND: Recent studies conducted in several OECD countries have shown that chronic exposure to elevated levels of air pollutants (especially PM2.5, PM10 and NOx), might negatively impact COVID-19 morbidity and mortality rates. The aim of this study was to examine the association between chronic exposure to air pollution in Israeli cities and towns, their demographic and socioeconomic status, and COVID-19 morbidity, during the three local morbidity waves. METHODS: We examined the associations between: (a) annual average concentrations of NOx, CO, PM10, PM2.5 and SO2 in 2016-2019, and demographic and socioeconomic parameters, and (b) COVID-19 positive cases in 279 Israeli cities and towns, in the four state-wide morbidity peaks: 1st wave peak: March 31st, 2020; 2nd wave peaks: July 24th and September 27th, 2020, and the 3rd wave peak: January 17th, 2021, which occurred after the beginning of the nationwide vaccination campaign. These associations were calculated using both Spearman correlations and multivariate linear regressions. RESULTS: We found statistically significant positive correlations between the concentrations of most pollutants in 2016-19 and COVID-19 morbidity rate at the first three timepoints but not the 4th (January 17th, 2021). Population density and city/town total population were also positively associated with the COVID-19 morbidity rates at these three timepoints, but not the 4th, in which socioeconomic parameters were more dominant - we found a statistically significant negative correlation between socioeconomic cluster and COVID-19 morbidity. In addition, all multivariate models including PM2.5 concentrations were statistically significant, and PM2.5 concentrations were positively associated with the COVID-19 morbidity rates in all models. CONCLUSIONS: We found a nationwide association between population chronic exposure to five main air pollutants in Israeli cities and towns, and COVID-19 morbidity rates during two of the three morbidity waves experienced in Israel. The widespread morbidity that was related to socioeconomic factors during the 3rd wave, emphasizes the need for special attention to morbidity prevention in socioeconomically vulnerable populations and especially in large household communities. Nevertheless, this ecological study has several limitations, such as the inability to draw conclusions about causality or mechanisms of action. The growing body of evidence, regarding association between exacerbated COVID-19 morbidity and mortality rates and long-term chronic exposure to elevated concentrations of air pollutants should serve as a wake-up call to policy makers regarding the urgent need to reduce air pollution and its harmful effects.

Effects of chronic exposure to ambient air pollutants on COVID-19 morbidity and mortality - A lesson from OECD countries.

BACKGROUND: Exposure to ambient air pollution is related to 4.2 million premature deaths per year worldwide and is associated with a variety of adverse health outcomes, such as respiratory and cardiovascular morbidity. Furthermore, exposure to air pollution can increase human sensitivity to respiratory pathogens via damage to the respiratory tract or via airborne transmission on the surface of particulate matter, and might be an additional factor influencing COVID-19 morbidity and mortality rates. The aim of this study was to examine the association between populations' exposure to air pollution and the morbidity and mortality rates from COVID-19. METHODS: We examined the association between population-weighted long-term exposure to PM2.5 and NOx, and the morbidity and mortality over time following the detection of the first COVID-19 positive case in 36 OECD countries. Pearson and Spearman correlations between daily COVID-19 morbidity and mortality (Jan-Jun 2020) on the 10th, 20th, 40th, 60th and 80th days since first confirmed case in the country, and demographic, health, economic, and environmental data were calculated. Multivariate linear regression were used to examine the associations between demographic, health, economic and air pollution features and the rate of confirmed cases and deaths on the 60th and 80th days following the first confirmed case. RESULTS: PM2.5 concentrations in 2015-2017 were positively correlated with COVID-19 morbidity and mortality on the 10th, 20th, 40th and 60th days since the first confirmed case in all countries. NOx concentrations in 2015-2017 and country's density (population/Km2) were positively correlated with COVID-19 morbidity and mortality on the 60th day. All multivariate linear regressions consisting PM2.5 concentrations models were statistically significant. Our models also emphasize the importance of the relative number of hospital beds in decreasing the morbidity and mortality of COVID-19. CONCLUSIONS: The adverse health outcomes stemming from long-term exposure to various air pollutants has long been known to the scientific community. According to our results and previously published studies, it appears that long-term exposure to air pollutants concentrations exceeding WHO guidelines, such as PM2.5 and NOx, might exacerbate morbidity and mortality rates from COVID-19. These results should raise a red flag globally among decision makers about the urgent need to reduce air pollution and its harmful effects.