Polysulphone film as an underwater dosimeter for solar ultraviolet-B radiation in tropical latitudes

Journal of Photochemistry and Photobiology B: Biology

Turnbull

2008

Various methodologies using a wide range of measurement systems have been employed previously in order to determine the amount of UV that could be incident upon various aquatic organisms in a number of different aquatic locales. Broadband meters and spectroradiometers have been employed extensively to take underwater measurements. However, these measurement campaigns are limited by the fact that radiometric equipment requires a human controller, constant power supply and regular calibrations and corrections in order to function properly. Dosimetric measurements have also been made underwater using two distinct types of dosimeter.The first type based on a synthetic chemical, like polysulphone, and the second type based on a biological matter, such as a DNA sample. The studies made using biological dosimeters have displayed very good results, however the time and skill necessary to make these types of dosimeters can outweigh their usefulness. The chemical dosimeters are easier to make and have also provided useable data, but only for short periods of exposure, usually no more than a day. Previous research has shown that Poly (2,6-dimethyl-1, 4-phenylene oxide) (PPO) has excellent potential for use as a long -term underwater solar UVB dosimeter. However, there is no documented methodology on how to properly calibrate the PPO dosimeter for waterbased measurements and it has yet to be trialled in an outdoors marine environment, either real or simulated. This manuscript shows that calibrations obtained in air can not be transferred to calibrations made in water, calibrations made in one type of water can be employed for another type of water, but only within a certain range of spectral transmission and calibrations made at different depths in the same water type are interchangeable. It was also discovered that changing solar zenith angle had an effect upon calibration data. This research addressed these issues by formulating and 2 developing a calibration methodology required for accurate underwater long -term UVB measurements in the field using the PPO film dosimeter.3

Section: Dose Response Calibrationsmentioning

confidence: 63%

“…The first and most commonly used is polysulphone. Dunne [12] evaluated UVB radiation with polysulphone dosimeters in a variety of different types of seawater at tropical latitudes. The author found that polysulphone had a practical depth range of between 2.2 and 7.0 m, dependent upon seawater turbidity with a 5% error margin.…”

Section: Introductionmentioning

confidence: 99%

Field calibrations of a long-term UV dosimeter for aquatic UVB exposures

Journal of Photochemistry and Photobiology B: Biology

Turnbull

2008

“…PS film dosimeters have been examined for underwater use previously and have a quoted UVB measurement error of less than 5% within tropical latitudes for most of the day (16). The absorbance of the PS dosimeters was measured pre and post exposure at 330 nm using a spectrophotometer (model 1601, Shimadzu Co., Kyoto, Japan).…”

Section: Methodsmentioning

confidence: 99%

Solar ultraviolet radiation incident upon reef snorkelers determined by consideration of the partial immersion of dosimeters in the natural ocean environment

Downs

2010

Meas. Sci. Technol.

Reef snorkeling is potentially a high risk activity for persons visiting tropical and sub-tropical waters due to possible overexposure to solar ultraviolet radiation (UVR have shown there to be some variation in the UVR distribution, with the neck receiving the greatest proportion of ambient UVR (0.56 ± 0.14 (1σ)), followed by the lower back (0.36 ± 0.14 (1σ)).Similarly high UVR exposures were determined at neck and lower back sites for different seasons, different times of day and over the latitudinal range of the study.3

“…The first was carried out by Dunne [15], where UVB radiation was measured using polysulphone dosimeters in seawater at tropical latitudes. The author discovered that the polysulphone dosimeters could obtain a UVB response within a 5% error threshold over a depth range of between 2.2 and 7.0 m, depending upon the turbidity of the seawater.…”

Section: Introductionmentioning

confidence: 99%

Applicability of the polyphenylene oxide film dosimeter to high UV exposures in aquatic environments

Journal of Photochemistry and Photobiology B: Biology

Turnbull

2009

Previous research has proven that the Poly (2,6-dimethyl-1, 4-phenylene oxide) (PPO) dosimeter is capable of receiving both in-air and underwater UV exposures that are significantly greater than those of the more commonly used polysulphone dosimeter, within a range of accuracy close to what would be expected of dosimetric measurements made in-air provided that the necessary calibrations are completed correctly by factoring in different atmospheric column ozone levels, SZA ranges, varying water turbidity and DOM levels. However, there is yet to be an investigation detailing the performance of the PPO dosimeter and its ability to measure UV in an actual field environment over an extended period of time. This research aims to bridge this gap in the knowledge by presenting a measurement campaign carried out in two real world aquatic environments and a simulated sea water environment using a batch of PPO dosimeters set at different depths and aligned to a range of different angles and geographical directions by means of attachment to a custom built dosimeter submersible float (DSF) unit over the space of a year at a sub-tropical location.Results obtained from this measurement campaign were used to compute a K d value for the sea water in each particular season. These K d values where found to be in close agreement to standalone K d values derived from results taken using a standard calibrated spectrometer in the same sea water.