Biomedical subjects

M G Kimlin

Publications and source records attributed to M G Kimlin.

27 records · Page 2Linked to original sources

PubMed1999

Ultraviolet radiation penetrating vehicle glass: a field based comparative study.

The solar UV transmitted through automobile glass was measured in the field in two cars using a spectroradiometer. The two cars were identical except that one of the cars had all of the windows (except the windshield) tinted. The measured spectral erythemal UV on a horizontal plane with the windows fully closed was reduced in the tinted car by a factor of 42 when compared with the erythemal UV measured in the untinted car. The ambient UVA irradiances at various locations within four different makes of car and a tractor were also measured with a broad band UVA handheld meter. The average normalized daily UVA exposure (measured with a broad band UVA meter) was 1.3 times higher in a large family sedan when compared with that in a small hatchback and the UVA exposure in a car with tinted windows was 3.8 times less than in a similar untinted car.

Glass↗

PubMed1999

Comparison of the spectral biologically effective solar ultraviolet in adjacent tree shade and sun.

The solar spectral UVR irradiances in tree shade and sunlight have been measured in a sub-tropical southern hemisphere summer. The spectral data allowed the UVB and UVA irradiances and the biologically effective irradiances to be calculated for different harmful biological processes to human skin and eyes. The average of the ratio of the UVA to UVB irradiances was lower by 26% in the shade compared with the same ratio in the sun. The spectral shade ratio calculated as the ratio of the spectral biologically effective irradiances in the shade to those in the adjacent sun decreased with increasing wavelength for all of the trees. The decrease in the shade ratio was approximately 42% at 400 nm compared with the shade ratio at 300 nm. Despite the UVR protection provided by tree shade, the erythemal UVR exposure received in 1 h in the tree shade exceeded the occupational limit for UVR exposure.

Animals↗

PubMed1999

Penetration of solar erythemal UV radiation in the shade of two common Australian trees.

The penetration of solar erythemal ultraviolet radiation has been measured in the shade of a gum (Eucalyptus sp.) and a she oak (Casaurina) tree, both on a horizontal plane and with polysulphone dosimeters to human anatomical sites. This has provided new data useful for protection strategies against harmful ultraviolet radiation. For larger solar zenith angles, the relative penetration of solar erythemal ultraviolet in the shade of the trees is higher. On a horizontal plane, at noon, in winter, the shade erythemal ultraviolet ranged from 44 to 55% of that in the sun whereas in spring it ranged from 29 to 37% of the irradiances in the sun. Similarly, at 9:00 EST and 15:00 EST, the shade erythemal ultraviolet in winter ranged from 51 to 81% of the irradiances in the sun whereas in spring and summer they ranged from 35 to 51% of the unshaded irradiances. The shade ratios for specific body sites provided by the shade of the two trees were 0.05 to 0.45 for the solar zenith angles in this research. The shade ratios ranged from 0.14 to 0.45 for the gum tree and from 0.05 to 0.28 for the she oak. The denser foliage of the she oak provided higher ultraviolet protection compared to that of the gum tree.

Australia↗

PubMed1999

Effect of stretch on the ultraviolet spectral transmission of one type of commonly used clothing.

The spectral ultraviolet (UV) transmission through stockings was measured in field and laboratory based trials using a spectroradiometer. From these spectral UV measurements, the ultraviolet protection factor (UPF) was calculated. The UPF of stockings measured in the field was generally higher than that measured in the laboratory when using a quartz tungsten halogen light as the UV source. The UPF of 50 denier stockings decreased 868% when stretched 30% from their original size. Doctors recommending and patients using high denier stockings for patient photoprotection should be aware of the dramatic decrease in UPF when the stocking is in a stretched position, such as over a human leg.

Clothing↗

PubMed1998

The facial distribution of erythemal ultraviolet exposure in south-east Queensland.

This paper presents a method for the evaluation of the distribution of the facial erythemal UV exposure and the erythemal UV exposure per unit area of the face using only eight dosimeters located on the vertex of the head, forehead, nose, chin, left and right ears and left and right cheeks. An overall picture of the parts of the face receiving high UV exposures is provided. The distribution of the erythemal UV exposure to the human face at a subtropical latitude was shown to change with time of year and with cloud cover. On two days with similar solar zenith angles, the ratio of the erythemal UV exposure to the nose compared with that on a horizontal plane changed from 0.47 to 0.84 with increased cloud cover. At the same time, the total erythemal exposure per unit area of the face dropped from 122 to 56 ml cm-2. Although the absolute exposures decreased, the nose received a relatively high exposure.

Erythema↗

PubMed1998

Simultaneous comparison of the personal UV exposure of two human groups at different altitudes.

A simultaneous comparison of human exposure to solar ultraviolet radiation at two locations was performed to study the effect of environmental factors and human attitudes on personal ultraviolet exposure. The study took place on 29 October 1996 in Toowoomba (27.5 degrees S, 151.9 degrees E) and Brisbane (27.4 degrees S, 153.1 degrees E), Queensland, Australia. From the data collected by calibrated ambient ultraviolet monitoring stations located in Toowoomba and Brisbane, Toowoomba received 68% more UVA (320-400 nm) and 61% more UVB (280-320 nm) than Brisbane from 07:00 to 10:00 Australian Eastern Standard Time (EST). From 10:00 to 17:00 EST Toowoomba received 5% more UVA and 20% less UVB than Brisbane. High ambient ultraviolet levels recorded by ultraviolet stations were reinforced by measurement of the personal ultraviolet exposure of human subjects wearing polysulfone dosimeters. Contrary to the common belief that the ultraviolet exposure to the human body is higher near the beach (i.e., coastal areas) than the inland area, the average erythemal weighted ultraviolet exposure on the chest and shoulder of each subject in the inland city of Toowoomba (127 km to the west of Brisbane) was 30% higher than in the coastal city of Brisbane from 07:00 to 17:00 EST. Evidence is also presented to suggest a relationship between altitude, climatic conditions, the human attitude, and the level of personal exposure to ultraviolet radiation.

Altitude↗

PubMed1998

Quantification of personal solar UV exposure of outdoor workers, indoor workers and adolescents at two locations in Southeast Queensland.

Quantification of human exposure to solar ultraviolet (UV) radiation at two locations was performed to study the effect of occupation (outdoor workers, schoolchildren and home workers) and location on personal UV exposure. The study took place on 13 and 14 February 1997 in Toowoomba (27.5 degrees S, 151.9 degrees E) and Brisbane (27.4 degrees S, 153.1 degrees E) in Southeast Queensland, Australia. From the data collected by calibrated ambient UV monitoring stations located in Toowoomba and Brisbane, Toowoomba received 16% more UVB (280-320 nm) than Brisbane from 07:00 to 17:00 Australian Eastern Standard Time (EST) on the 13 February, 1997 and 10% more UVB on the 14 February 1997. All groups, regardless of occupation, in this study received a median erythemal UV exposure of over 2 MED on the shoulder over the 2 day period. The highest median erythemal UV exposure to the shoulder over the 2 day period was 6 MED in Toowoomba outdoor workers. The median 2 day erythemal exposure to the shoulder was 33% higher in Toowoomba than in Brisbane for the outdoor workers, 50% higher in Toowoomba compared to Brisbane for the schoolchildren and 25% higher in Toowoomba than Brisbane for the home workers.

Adolescent↗

PubMed1996

The effects of body size and orientation on ultraviolet radiation exposure.

A method has been developed for determining the UV and erythemal exposures to the entire body. The difference between the ambient erythemal exposure and that to the body compared to the ambient exposure may be as high as 76%. The height, orientation, and overall height had a minimal effect on the exposure to the body with size, time of day and time of year having a significant effect. The diffuse component of UV to a side of the body ranged from 20% to 41% between different times of the year with different levels of cloud cover. The ratio of the body to the ambient erythemal exposures varied from 0.24 to 0.61, with the time of day and time of year with the smaller value for periods of high solar altitude.

Body Constitution↗

PubMedDate not supplied

Horizontal and sun-normal spectral biologically effective ultraviolet irradiances.

The dependence of the spectral biologically effective solar UV irradiance on the orientation of the receiver with respect to the sun has been determined for relatively cloud-free days at a sub-tropical Southern Hemisphere latitude for the solar zenith angle range 35-64 degrees. For the UV and biologically effective irradiances, the sun-normal to horizontal ratio for the total UV ranges from 1.18 +/- 0.05 to 1.27 +/- 0.06. The sun-normal to horizontal ratio for biologically effective irradiance is dependent on the relative effectiveness of the relevant action spectrum in the UV-A waveband. In contrast to the total UV, the diffuse UV and diffuse biologically effective irradiances are reduced in a sun-normal compared with a horizontal orientation by a factor ranging from 0.70 +/- 0.05 to 0.76 +/- 0.03.

Humans↗