Spatiotemporal exposure modeling of ambient erythemal ultraviolet radiation

Abstract

BackgroundUltraviolet B (UV-B) radiation plays a multifaceted role in human health, inducing DNA damage and representing the primary source of vitamin D for most humans; however, current U.S. UV exposure models are limited in spatial, temporal, and/or spectral resolution. Area-to-point (ATP) residual kriging is a geostatistical method that can be used to create a spatiotemporal exposure model by downscaling from an area- to point-level spatial resolution using fine-scale ancillary data.MethodsA stratified ATP residual kriging approach was used to predict average July noon-time erythemal UV (UVEry) (mW/m2) biennially from 1998 to 2012 by downscaling National Aeronautics and Space Administration (NASA) Total Ozone Mapping Spectrometer (TOMS) and Ozone Monitoring Instrument (OMI) gridded remote sensing images to a 1 km spatial resolution. Ancillary data were incorporated in random intercept linear mixed-effects regression models. Modeling was performed separately within nine U.S. regions to satisfy stationarity and account for locally varying associations between UVEry and predictors. Cross-validation was used to compare ATP residual kriging models and NASA grids to UV-B Monitoring and Research Program (UVMRP) measurements (gold standard).ResultsPredictors included in the final regional models included surface albedo, aerosol optical depth (AOD), cloud cover, dew point, elevation, latitude, ozone, surface incoming shortwave flux, sulfur dioxide (SO2), year, and interactions between year and surface albedo, AOD, cloud cover, dew point, elevation, latitude, and SO2. ATP residual kriging models more accurately estimated UVEry at UVMRP monitoring stations on average compared to NASA grids across the contiguous U.S. (average mean absolute error [MAE] for ATP, NASA: 15.8, 20.3; average root mean square error [RMSE]: 21.3, 25.5). ATP residual kriging was associated with positive percent relative improvements in MAE (0.6–31.5%) and RMSE (3.6–29.4%) across all regions compared to NASA grids.ConclusionsATP residual kriging incorporating fine-scale spatial predictors can provide more accurate, high-resolution UVEry estimates compared to using NASA grids and can be used in epidemiologic studies examining the health effects of ambient UV.Electronic supplementary materialThe online version of this article (doi:10.1186/s12940-016-0197-x) contains supplementary material, which is available to authorized users.

Ozone—climate interactions and effects on solar ultraviolet radiation

“…This downscaling was achieved by interpolation of satellite data and other measurements (e.g., surface albedo, aerosol optical depth, cloud cover, dew point, ozone, surface incoming shortwave flux, and sulfur dioxide). 210 Such higher resolution data can be more useful in studies where UV radiation data at specific locations are needed.…”

Ambient ultraviolet radiation exposure and hepatocellular carcinoma incidence in the United States

“…Additional studies examining individual-level exposure of vitamin D and HCC risk are needed. We used a high-resolution spatiotemporal UV model validated against ground truth UV monitoring data [ 35 ] to estimate exposure and exposure was assessed similarly across all counties in the study. Further, counties have been used in previous epidemiologic studies as geographic variables capturing activity space, or the local areas within which people move or travel during the course of their daily activities interacting with their environment [ 88 , 89 ].…”

“…Erythemal UV incorporates UV-A and UV-B wavelengths (involved in vitamin D production) to calculate a measure describing the relative effectiveness of UV to induce erythema on Caucasian skin; shorter UV-B wavelengths are weighted more in the calculation [ 36 , 37 ]. July erythemal UV has been predictive of risk for skin, colorectal, and other cancers in previous epidemiologic studies [ 22 , 24 , 25 , 38 ], and during July, erythemal UV is strongest, aerosols and other noise factors are less influential, and satellite-based measures are in better agreement with ground-based measures [ 25 , 35 ]. The UV exposure model spans the contiguous U.S.…”

“…Ambient UV exposure was estimated for each county in the study area using a high spatiotemporal resolution UV model [ 35 ]. The model was created using area-to-point residual kriging to downscale National Aeronautics and Space Administration (NASA) erythemal UV satellite remote sensing images from the Total Ozone Mapping Spectrometer (TOMS) and Ozone Monitoring Instrument (OMI) satellite sensors.…”

Personal use of permanent hair dyes and cancer risk and mortality in US women: prospective cohort study

“…We considered age, race, natural hair color, cumulative average body mass index, body mass index at age 18, smoking status, pack years of smoking, and alcohol intake as common confounders in analyses of all cancers. For more complete control of confounding, we also controlled for the following endpoint specific covariates in multivariable analyses of individual cancers and cancer death: physical activity, intake of total calories, total fluid, red or processed meat, fiber, folate, calcium and vitamin D, regular use of aspirin, non-aspirin nonsteroidal anti-inflammatory drugs, use of multivitamins, postmenopausal hormones and oral contraceptives, menopausal status, adolescent body size, age at menarche and first birth, parity, history of breastfeeding, current mammography use, screening colonoscopy or sigmoidoscopy in the previous two years, childhood reaction to sun, lifetime blistering sunburns, number of moles on arms, cumulative ultraviolet flux since baseline,2728 history of hypertension, hypercholesterolemia, diabetes mellitus and breast disease, and family history of colorectal cancer and breast cancer. The validity and reproducibility of these covariates have been described previously 192021222324.…”