Showing papers by "Marina Neophytou published in 2021"

The MEDEA childhood asthma study design for mitigation of desert dust health effects: implementation of novel methods for assessment of air pollution exposure and lessons learned.

Abstract: Desert dust events in Mediterranean countries, originating mostly from the Sahara and Arabian deserts, have been linked to climate change and are associated with significant increase in mortality and hospital admissions from respiratory causes. The MEDEA clinical intervention study in children with asthma is funded by EU LIFE+ program to evaluate the efficacy of recommendations aiming to reduce exposure to desert dust and related health effects. This paper describes the design, methods, and challenges of the MEDEA childhood asthma study, which is performed in two highly exposed regions of the Eastern Mediterranean: Cyprus and Greece-Crete. Eligible children are recruited using screening surveys performed at primary schools and are randomized to three parallel intervention groups: a) no intervention for desert dust events, b) interventions for outdoor exposure reduction, and c) interventions for both outdoor and indoor exposure reduction. At baseline visits, participants are enrolled on MEDena® Health-Hub, which communicates, alerts and provides exposure reduction recommendations in anticipation of desert dust events. MEDEA employs novel environmental epidemiology and telemedicine methods including wearable GPS, actigraphy, health parameters sensors as well as indoor and outdoor air pollution samplers to assess study participants’ compliance to recommendations, air pollutant exposures in homes and schools, and disease related clinical outcomes. The MEDEA study evaluates, for the first time, interventions aiming to reduce desert dust exposure and implement novel telemedicine methods in assessing clinical outcomes and personal compliance to recommendations. In Cyprus and Crete, during the first study period (February–May 2019), a total of 91 children participated in the trial while for the second study period (February–May 2020), another 120 children completed data collection. Recruitment for the third study period (February–May 2021) is underway. In this paper, we also present the unique challenges faced during the implementation of novel methodologies to reduce air pollution exposure in children. Engagement of families of asthmatic children, schools and local communities, is critical. Successful study completion will provide the knowledge for informed decision-making both at national and international level for mitigating the health effects of desert dust events in South-Eastern Europe. ClinicalTrials.gov: NCT03503812 , April 20, 2018.

Exploring the multi-fractal nature of the air flow and pollutant dispersion in a turbulent urban atmosphere and its implications for long range pollutant transport.

Abstract: This work investigates the multi-fractal nature of a turbulent urban atmosphere using high-resolution atmospheric data. Meteorological and concentration measurements of passive and reactive pollutants collected over a 3-year period in a sub-urban high-Reynolds number atmospheric field were analyzed. Scaling laws characterizing the self-similarity and thereby depicting the multi-fractal nature are determined by calculating the singularity spectra, where a range of Holder exponents, h, are estimated. In doing so, the complexity of the urban atmosphere entailing different stability regimes was addressed. Using the Monin-Obukhov length ( L M O) as a marker of atmospheric stability and thereby an indication of the magnitude of anisotropy, we find where and how self-similarity is manifested relative to the different regimes and we estimate corresponding appropriate scaling laws. We find that the wind speed obeys the − 5 / 3 law suggested by Kolmogorov only when the atmosphere lies within the stable regime as defined by Monin-Obukhov theory. Specifically, when the ratio of the atmospheric boundary layer height ( H b . l) over L M O is greater than 15, and at the same time, the ratio of the height above ground of the wind measurements ( z 0) over L M O is higher than 3 (i.e., in stable regime), then the singularity spectra of wind speed time series indicate that the dominant Holder exponent, h max, coincides with Kolmogorov’s second hypothesis. On the contrary under unstable regimes in the atmosphere where the anisotropy is approached, different scaling laws are estimated. In detail, when z 0 / L M O < 0, the dominant Holder exponent, h max, of the singularity spectra of the wind speed time series is either negative or close to zero, which is an indication of an impulse-like singularity, that is associated with rapid changes. For the ambient temperature and air quality measurements such as of carbon monoxide and particulate matter concentrations, it was found that they obey different laws, which are related with the long-term correlation of their data fluctuation.

The Impact on Urban Air Quality of the COVID-19 Lockdown Periods in 2020: The Case of Nicosia, Cyprus

Abstract: The purpose of this study is to assess the impact of the lockdown measures in 2020 on the urban air quality in Nicosia capital city, in Cyprus—an island-country in the East Mediterranean—which is often affected by transboundary dust pollution. The study focuses on three criteria pollutants, nitrogen dioxide (NO2), carbon monoxide (CO) and Particulate Matter (PM10), taken from three Air Quality Monitoring Stations; two urban stations and one reference-background. The results of this study show that the decrease in traffic, which is the main source of high concentrations of pollutants in the urban area, reached up to 66.5% during the lockdown. At the beginning of the lockdown period, it exhibited a downward trend of 29% for CO concentration, and downward trend 43% for NO2 and PM10 concentrations. The NO2 concentration exhibited an upward trend towards the end of the lockdown; with the indication that this was due to meteorological conditions relevant to the monitoring stations and the transport of NO2 concentrations from sources that cannot be tracked. PM10 concentrations exhibited a varying behaviour as observed in the trends, where the decreasing trend was followed by an increasing trend due to transboundary air pollution episodes occurring in the same period.