Modeling Desert Dust Exposures in Epidemiologic Short-term Health Effects Studies

Abstract

Background: Desert dust is assumed to have substantial adverse effects on human health. However, the epidemiologic evidence is still inconsistent, mainly because previous studies used different metrics for dust exposure and its corresponding epidemiologic analysis. We aim to provide a standardized approach to the methodology for evaluating the short-term health effects of desert dust. Methods: We reviewed the methods commonly used for dust exposure assessment, from use of a binary metric for the occurrence of desert dust advections to a continuous one for quantifying particulate matter attributable to desert dust. We presented alternative time-series Poisson regression models to evaluate the dust exposure–mortality association, from the underlying epidemiological and policy-relevant questions. A set of practical examples, using a real dataset from Rome, Italy, illustrate the different modeling approaches. Results: We estimate substantial effects of desert dust episodes and particulate matter with diameter <10 μm (PM10) on daily mortality. The estimated effect of non-desert PM10 was 1.8% (95% confidence interval [CI] = 0.4, 3.2) for a 10 μg/m3 rise of PM10 at lag 0 for dust days, 0.4% (95% CI = −0.1, 0.8) for non-dust days, and 0.6% (95% CI = −0.5, 2.1) for desert PM10. Conclusion: The standardized modeling approach we propose could be applicable elsewhere, in and near hot spots, which could lead to more consistent evidence on the health effects of desert dust from future studies.

Dust from the Sahara to the American Continent: Health impacts

“…20 Thus, it would become increasingly necessary to have a standardized approach through spatial indicators, potentially useful, to be able to characterize environmental exposures and the health effects of populations that are impacted by the desert dust. 24,25 Exposure to SahD and health impacts WHO marks air pollution as a global health priority. It is estimated that 1.4% of the world's deaths result from exposure to PM from both natural sources( like dust lifted from the soil) and anthropogenic sources( like the burning of fossil fuels).…”

“…15,45 Indeed, a standardized approach to the methodology for evaluating the short-term health effects of desert dust has been recently proposed. 24,25 Desert dust particles also carry potential microbial agents, such as bacteria, fungi, and viruses, 28 that survive long-range transport, enriching the airborne microbiome with new soil-derived microorganisms causing health implications. 46,47 Many bacteria isolated from soil dust aerosol samples are highly pigmented, suggesting that, besides the protection provided by clouds, fog, smoke, and desert dust particles, pigmentation also helps protect microbes from ultraviolet (UV) radiation.…”

“…Studies suggest that dust storms that occurring in the southwestern United States are related to this fungal disease, which mainly affects the lungs and can be potentially fatal. 25 Indeed, it presents a bimodal seasonality that coincides with the driest and dustiest months in California and Arizona. 12 Several mechanisms contribute to the microbial load of African desert dust as it moves across the continents:…”

COST Lecture 2019 AE GM Barcelona: International Network to Encourage the Use of Monitoring and Forecasting Dust Products (InDust)

“…For health, Tobias and Stafoggia (2020) reviewed the exposure metric used to investigate the health effects of desert dust. Dust exposure can be defined using a binary metric and comparing the number of health events between days with and without dust events.…”

Airborne Bacterial Community Composition According to Their Origin in Tenerife, Canary Islands

“…The presence of microorganisms in the atmosphere not only has consequences for environmental health issues ( Karanasiou et al, 2012 ; Zhang et al, 2016 ; Tobías and Stafoggia, 2020 ) but may also affect the climate ( Bowers et al, 2009 ). For instance, their role in the formation of ice nuclei has been considered important at low latitudes, where tropospheric temperatures can be too high to allow abiotic particles to efficiently act as ice nucleators ( Spracklen and Heald, 2014 ), whereas some of the common genera found in airborne samples, such as Pseudomonas or Bacillus , are known as capable cloud condensation nuclei ( Ariya and Amyot, 2004 ).…”