TY  - CONF
AU  - Preez, David Jean du
AU  - Blesic, Suzana
AU  - Wright, Caradee Y.
AU  - Stratimirović, Djordje
AU  - Ajtić, Jelena
AU  - Allen, Martin
AU  - Bencherif, Hassan
PY  - 2020
UR  - https://vet-erinar.vet.bg.ac.rs/handle/123456789/2340
AB  - We investigated scaling properties of measurements of personal exposure to solar ultraviolet radiation (pUVR) using the 2nd order detrended fluctuation analysis (DFA2) and the wavelet transform spectral analysis (WTS). Studies of pUVR are important to identify populations at-risk of excess and insufficient exposure given the negative and positive health impacts, respectively, of time spent in the sun. These very high frequency recordings are collected by electronic UVR dosimeters. We analyzed sun exposure patterns of school children in South Africa and construction workers and work site supervisors in New Zealand, and we found scaling behavior in all our data. The observed scaling changed from uncorrelated to long-range correlated with increasing duration of sun exposure. We found peaks in the WTS spectra that mark characteristic times in pUVR behavior, which may be connected to both human outside activity and natural (solar) daily cycles. We further hypothesized that the WT slope would be influenced by the duration of time that a person spends in continuum outside and addressed this hypothesis by using an experimental study approach. To that end we performed combined DFA2-WTS analysis on a subset of individual records taken on the same day under very similar outdoor conditions and used the theoretical superposition rule provided by systematic assessments of effects of trends and nonstationarities on DFA2 as a methodological mean to trace and subsequently model human behavioral patterns in pUVR time series.
PB  - Copernicus Meetings
C3  - EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-303
T1  - Characterization of human behavior in records of personal solar ultraviolet exposure records
DO  - 10.5194/egusphere-egu2020-303
ER  - 

@conference{
author = "Preez, David Jean du and Blesic, Suzana and Wright, Caradee Y. and Stratimirović, Djordje and Ajtić, Jelena and Allen, Martin and Bencherif, Hassan",
year = "2020",
abstract = "We investigated scaling properties of measurements of personal exposure to solar ultraviolet radiation (pUVR) using the 2nd order detrended fluctuation analysis (DFA2) and the wavelet transform spectral analysis (WTS). Studies of pUVR are important to identify populations at-risk of excess and insufficient exposure given the negative and positive health impacts, respectively, of time spent in the sun. These very high frequency recordings are collected by electronic UVR dosimeters. We analyzed sun exposure patterns of school children in South Africa and construction workers and work site supervisors in New Zealand, and we found scaling behavior in all our data. The observed scaling changed from uncorrelated to long-range correlated with increasing duration of sun exposure. We found peaks in the WTS spectra that mark characteristic times in pUVR behavior, which may be connected to both human outside activity and natural (solar) daily cycles. We further hypothesized that the WT slope would be influenced by the duration of time that a person spends in continuum outside and addressed this hypothesis by using an experimental study approach. To that end we performed combined DFA2-WTS analysis on a subset of individual records taken on the same day under very similar outdoor conditions and used the theoretical superposition rule provided by systematic assessments of effects of trends and nonstationarities on DFA2 as a methodological mean to trace and subsequently model human behavioral patterns in pUVR time series.",
publisher = "Copernicus Meetings",
journal = "EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-303",
title = "Characterization of human behavior in records of personal solar ultraviolet exposure records",
doi = "10.5194/egusphere-egu2020-303"
}

Preez, D. J. d., Blesic, S., Wright, C. Y., Stratimirović, D., Ajtić, J., Allen, M.,& Bencherif, H.. (2020). Characterization of human behavior in records of personal solar ultraviolet exposure records. in EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-303
Copernicus Meetings..
https://doi.org/10.5194/egusphere-egu2020-303

Preez DJD, Blesic S, Wright CY, Stratimirović D, Ajtić J, Allen M, Bencherif H. Characterization of human behavior in records of personal solar ultraviolet exposure records. in EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-303. 2020;.
doi:10.5194/egusphere-egu2020-303 .

Preez, David Jean du, Blesic, Suzana, Wright, Caradee Y., Stratimirović, Djordje, Ajtić, Jelena, Allen, Martin, Bencherif, Hassan, "Characterization of human behavior in records of personal solar ultraviolet exposure records" in EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-303 (2020),
https://doi.org/10.5194/egusphere-egu2020-303 . .

TY  - CONF
AU  - Preez, David Jean du
AU  - Blesic, Suzana
AU  - Wright, Caradee Y.
AU  - Stratimirović, Djordje
AU  - Ajtić, Jelena
AU  - Allen, Martin
AU  - Bencherif, Hassan
PY  - 2020
UR  - https://vet-erinar.vet.bg.ac.rs/handle/123456789/2341
AB  - Exposure to solar ultraviolet radiation (UVR) has health benefits such as vitamin D production but excess exposure can lead to sunburn, cataracts and skin cancer Risk factors associated with sun exposure can be limited by using sun protection measures Personal sun exposure differs from ambient UVR as it is influenced by behavior, movement and bodily location which are an indication of individual exposure behavior
T1  - Characterization of human behavior in records of personal solar ultraviolet exposure records: poster
UR  - https://hdl.handle.net/21.15107/rcub_veterinar_2341
ER  - 

@conference{
author = "Preez, David Jean du and Blesic, Suzana and Wright, Caradee Y. and Stratimirović, Djordje and Ajtić, Jelena and Allen, Martin and Bencherif, Hassan",
year = "2020",
abstract = "Exposure to solar ultraviolet radiation (UVR) has health benefits such as vitamin D production but excess exposure can lead to sunburn, cataracts and skin cancer Risk factors associated with sun exposure can be limited by using sun protection measures Personal sun exposure differs from ambient UVR as it is influenced by behavior, movement and bodily location which are an indication of individual exposure behavior",
title = "Characterization of human behavior in records of personal solar ultraviolet exposure records: poster",
url = "https://hdl.handle.net/21.15107/rcub_veterinar_2341"
}

Preez, D. J. d., Blesic, S., Wright, C. Y., Stratimirović, D., Ajtić, J., Allen, M.,& Bencherif, H.. (2020). Characterization of human behavior in records of personal solar ultraviolet exposure records: poster. .
https://hdl.handle.net/21.15107/rcub_veterinar_2341

Preez DJD, Blesic S, Wright CY, Stratimirović D, Ajtić J, Allen M, Bencherif H. Characterization of human behavior in records of personal solar ultraviolet exposure records: poster. 2020;.
https://hdl.handle.net/21.15107/rcub_veterinar_2341 .

Preez, David Jean du, Blesic, Suzana, Wright, Caradee Y., Stratimirović, Djordje, Ajtić, Jelena, Allen, Martin, Bencherif, Hassan, "Characterization of human behavior in records of personal solar ultraviolet exposure records: poster" (2020),
https://hdl.handle.net/21.15107/rcub_veterinar_2341 .

TY  - JOUR
AU  - du Preez, David J.
AU  - Ajtić, Jelena
AU  - Bencherif, Hassan
AU  - Begue, Nelson
AU  - Cadet, Jean-Maurice
AU  - Wright, Caradee
PY  - 2019
UR  - https://vet-erinar.vet.bg.ac.rs/handle/123456789/1743
AB  - The correlation between solar ultraviolet radiation (UV) and atmospheric ozone is well understood. Decreased stratospheric ozone levels which led to increased solar UV radiation levels at the surface have been recorded. These increased levels of solar UV radiation have potential negative impacts on public health. This study was done to determine whether the break-up of the Antarctic ozone hole has an impact on stratospheric columnar ozone (SCO) and resulting ambient solar UV-B radiation levels at Cape Point, South Africa, over 2007-2016. We investigated the correlations between UV index, calculated from ground-based solar UV-B radiation measurements and satellite-retrieved column ozone data. The strongest anti-correlation on clear-sky days was found at solar zenith angle 25 degrees with exponential fit R-2 values of 0.45 and 0.53 for total ozone column and SCO, respectively. An average radiation amplification factor of 0.59 across all SZAs was calculated for clear-sky days. The MIMOSA-CHIM model showed that the polar vortex had a limited effect on ozone levels. Tropical air masses more frequently affect the study site, and this requires further investigation.
PB  - Copernicus Gesellschaft Mbh, Gottingen
T2  - Annales Geophysicae
T1  - Spring and summer time ozone and solar ultraviolet radiation variations over Cape Point, South Africa
VL  - 37
IS  - 2
SP  - 129
EP  - 141
DO  - 10.5194/angeo-37-129-2019
ER  - 

@article{
author = "du Preez, David J. and Ajtić, Jelena and Bencherif, Hassan and Begue, Nelson and Cadet, Jean-Maurice and Wright, Caradee",
year = "2019",
abstract = "The correlation between solar ultraviolet radiation (UV) and atmospheric ozone is well understood. Decreased stratospheric ozone levels which led to increased solar UV radiation levels at the surface have been recorded. These increased levels of solar UV radiation have potential negative impacts on public health. This study was done to determine whether the break-up of the Antarctic ozone hole has an impact on stratospheric columnar ozone (SCO) and resulting ambient solar UV-B radiation levels at Cape Point, South Africa, over 2007-2016. We investigated the correlations between UV index, calculated from ground-based solar UV-B radiation measurements and satellite-retrieved column ozone data. The strongest anti-correlation on clear-sky days was found at solar zenith angle 25 degrees with exponential fit R-2 values of 0.45 and 0.53 for total ozone column and SCO, respectively. An average radiation amplification factor of 0.59 across all SZAs was calculated for clear-sky days. The MIMOSA-CHIM model showed that the polar vortex had a limited effect on ozone levels. Tropical air masses more frequently affect the study site, and this requires further investigation.",
publisher = "Copernicus Gesellschaft Mbh, Gottingen",
journal = "Annales Geophysicae",
title = "Spring and summer time ozone and solar ultraviolet radiation variations over Cape Point, South Africa",
volume = "37",
number = "2",
pages = "129-141",
doi = "10.5194/angeo-37-129-2019"
}

du Preez, D. J., Ajtić, J., Bencherif, H., Begue, N., Cadet, J.,& Wright, C.. (2019). Spring and summer time ozone and solar ultraviolet radiation variations over Cape Point, South Africa. in Annales Geophysicae
Copernicus Gesellschaft Mbh, Gottingen., 37(2), 129-141.
https://doi.org/10.5194/angeo-37-129-2019

du Preez DJ, Ajtić J, Bencherif H, Begue N, Cadet J, Wright C. Spring and summer time ozone and solar ultraviolet radiation variations over Cape Point, South Africa. in Annales Geophysicae. 2019;37(2):129-141.
doi:10.5194/angeo-37-129-2019 .

du Preez, David J., Ajtić, Jelena, Bencherif, Hassan, Begue, Nelson, Cadet, Jean-Maurice, Wright, Caradee, "Spring and summer time ozone and solar ultraviolet radiation variations over Cape Point, South Africa" in Annales Geophysicae, 37, no. 2 (2019):129-141,
https://doi.org/10.5194/angeo-37-129-2019 . .