Patterns in surface distribution of human exposure to solar ultraviolet

[Abstract]: A method for the three dimensional representation of erythemally effective ultraviolet radiation (UVery) incident to the human body has been developed from a series of polysulphone dosimeter (PS) measurements to the face, neck, arms, legs and hands of a manikin model. The technique has been used to represent a series of human UVery exposure patterns in the solar zenith angle (SZA) range 30o-50o measured in an open environment in Toowoomba, Australia (27.5oS 151.9oE). The human body representations of exposure presented here improve upon existing techniques to represent the UVery exposure to complex body shape topography, providing for the first time, estimates of exposure that take whole body shading effects into account from high density PS dosimeter measurements

Patterns in the received facial UV exposure of school children measured at a subtropical latitude

Polysulphone dosimeters have been employed to measure the erythemally effective UV exposure to the vertex, nose, cheek, chin and side facial sites of 45 volunteer high school students from Hervey Bay, Australia (25.3oS 152.9oE). The results of a series of 1 hour outdoor sport trials (basketball and soccer) found the mean student facial exposure, determined as the arithmetic average of facial site exposures of unprotected students (no hat) to protected students (hat) varied from 140 82 Jm-2 (1σ), to 99 33 Jm-2 (1σ) respectively. All hourly student facial exposures recorded over the study period were found to exceed the National Health and Medical Research Council’s adopted safe daily limit of 30 Jm-2. Facial exposure relative to the received ambient UV increased to the nose at higher (winter) Solar Zenith Angles (SZA) compared with lower (summer) SZA ranges for both protected and unprotected students. The protection offered by the broad-brimmed hats was reduced significantly to the lower chin facial site at the higher SZA range, indicating that the style of hat used offers best protection in summer to the upper facial regions at most risk of receiving a high exposure when no hat protection is used. Variations to specific student facial exposure sites were measured between both basketball and soccer players. Variation in student facial exposure was further examined with respect to cloud cover and comparisons to manikin headform measurements were also made. The study results indicate that hats alone are not adequate forms of sun protection in a school environment. Schools aiming to achieve acceptable safe limits of facial exposure may need to further consider the effectiveness of hat protection with increasing SZA, cloud cover and head position relative to the sun that is specific to the scheduled outdoor activity

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Corporate Inversio

Progress towards an industry standard for sun-protective clothing incorporating body coverage

Clothing provides a protective barrier that reduces the amount of ultraviolet radiation (UVR) reaching the skin. Although swim-shirts have grown in popularity in Australia particularly among children, clothing remains under-utilized as a form of sun-protection in contemporary society. Australia pioneered the relative ranking describing the sun-protective capabilities of clothing based on UVR-transmission through fabric. Ultraviolet Protection Factor (UPF) measurement procedures and associated labelling specifications are documented in the Australian and New Zealand Standard, AS/NZS 4399:1996. This standard was introduced in 1996 with the intention of enabling consumers to make informed choices, and has since been adopted universally by the textile industry. Our RCT showing that fewer new pigmented moles (major risk-factor for melanoma) developed on body-sites routinely covered by 'very good' to 'excellent-UPF rated clothing' in childhood, suggest that the proportion of the body’s surface covered by a garment should be articulated to consumers, on the standardised swing-tag attached to the garment, in addition to fabric UPF. This would better enable consumers to make informed choices about the sun-protective advantage of certain garments. This translational research project aims at develop a reproducible, practical and cost-effective solution to assessing garment surface area, to make the inclusion of the body surface coverage of garments a feasible proposition for inclusion in future industry standards. Collaboration with the fashion industry is also needed to improve the aesthetic appeal, comfort, durability and affordability of sun-protective clothing which covers a significant body surface area, in order to increase its popularity in skin cancer prone populations

Alternative methods for the reduction of evaporation: practical exercises for the science classroom

Across the world, freshwater is valued as the most critically important natural resource, as it is required to sustain the cycle of life. Evaporation is one of the primary environmental processes that can reduce the amount of quality water available for use in industrial, agricultural and household applications. The effect of evaporation becomes intensified especially during conditions of drought, particularly in traditionally arid and semi-arid regions, such as those seen in a number of countries over the past 10 years. In order to safeguard against the influence of droughts and to save water from being lost to the evaporative process, numerous water saving mechanisms have been developed and tested over the past century. Two of the most successful and widely used mechanisms have included floating hard covers and chemical film monolayers. This paper describes a laboratory based project developed for senior high school and first year university classes, which has been designed to introduce students to the concepts of evaporation, evaporation modelling and water loss mitigation. Specifically, these ideas are delivered by simulating the large-scale deployment of both monolayers and floating hard covers on a small water tank under numerous user defined atmospheric and hydrodynamic conditions, including varying surface wind speeds and underwater bubble plumes set to changing flow rates

Solar ultraviolet attenuation during the Australian (Red Dawn) dust event of 23 September 2009

The large dust event of 23 September 2009 is recognized as the most significant on record in Australia since the 1940s. At its peak, reported hourly average particulate concentrations exceeded 15000 ugm-3, significantly exceeding the Australian National Air Quality Standard of 50 ugm-3 and daily September averages of 20 - 25 ugm-3. Measurements of the spectral surface ultraviolet irradiance monitored continuously before, after and during the event of 23 September 2009 are presented. These measurements highlight the significance of extreme dust load on the ultraviolet irradiance, and exceed previously published UV attenuations measured in Saharan and Chinese dust events. Measured spectral attenuations of up to 99.5% in the ultraviolet-B and 97.6% in the ultraviolet-A, were associated with the arrival of low altitude cumuliform cloud and the dust plume ahead of an approaching cold front on the morning of 23 September 2009. The data presented covers the period of maximum attenuation and the afternoon which had no cloud cover. This research characterizes for the first time the influence of a frontal desert dust storm on the surface ultraviolet irradiance in the naturally high ambient ultraviolet climate of sub-tropical Australia

Annual measurement of solar UVB at a reef site using a polyphenylene oxide dosimeter

Numerous investigations detailed over the last thirty years have highlighted how solar UV (290-400 nm) can have a detrimental effect on coral health. It has also been postulated that coral bleaching is caused by a synergistic process between high water temperatures and increases in UV. As a consequence of its influence upon coral ecosystems, UV radiation must be monitored in underwater locations using an appropriate non-invasive measurement technique in order to better understand the damage it causes on both a macro and micro scale and provide solutions on how to adequately manage its impact. The high energy UVB waveband (290-320 nm) is believed to have the greatest negative influence on coral stress. This report details the employment of a simple, easily deployable UVB measuring dosimeter system based on polyphenylene oxide (PPO) at a coral reef location near Hervey Bay (25°17 S, 152°52′ E) over the interval of one year. Continual deployment of the PPO dosimeters measured a clear inverse correlation between tide level and UVB penetration, with the highest coral UVB exposures measured during the months of winter and spring (coinciding with typically lower tidal conditions during this time). This suggests that the UVB incident on Queensland coral reefs may not be strictly dependent on solar zenith angle (the Sun’s position in the sky), which is generally the primary factor in determining the extent of terrestrial UVB exposures. Further, this may mean that photo-damage incident on corals could be exacerbated in traditionally cooler months if current global warming trends continue

Human UVA exposures estimated from ambient UVA measurements

[Abstract]: The methods presented in this paper allow for the estimation of human UVA exposure using measured UVA irradiance values. Using measured broadband UVA irradiances over the period of a year, it was estimated that for humans in an upright posture and not moving the head with respect to the body, the nose received 26.5% of the available ambient UVA radiation, whilst the shoulders and vertex of the head received 81% and 100% respectively of the available ambient UVA radiation. Measurement of the exposure ratios for a series of solar zenith angles between 90o and 0o will allow extension of this technique to other latitudes

Dosimeter based on 8-Methoxypsoralen for UVA exposures over extended periods

A miniaturized UVA dosimeter based on 8-methoxypsoralen (8-MOP) has been developed and characterized for the evaluation of UVA (320 - 400 nm) exposures over extended periods longer than one day. Current research indicates that UVA is a contributing factor in non-melanoma skin cancers and the associated financial cost of damage caused by UVA is significant. Dosimetry is a technique that is commonly employed to measure UV exposures to an object or subject. Miniaturized dosimeters using polyphenylene oxide (PPO) have previously been used to measure received erythemal UV (UVery) exposures. A new miniaturized dosimeter using 8-MOP as the photoactive material has been characterized and a technique developed for the calibration of UVA exposures. Using Mylar as a UVB filter the spectral response showed 8-MOP to react only to wavelengths between 320 - 400 nm. The measured cosine response has an error of less than 13.8% for angles between 0° and 60°. Seasonal dose response tests conducted, indicate that these UVA dosimeters are able to measure exposures < 4.6 kJ/m2. These results have shown that a dosimeter constructed from 8-MOP in conjunction with a Mylar filter can measure UVA exposures over extended periods longer than one day