Analysis of chemical and physical effects of ultraviolet bulbs on cooking emissions.

There is a growing recognition of the risks to health, fire hazard, and air quality from cooking emissions. Recent research has identified what is emitted when foods are cooked. Some of the emitted mass is captured in the exhaust system. The balance is expelled into the atmosphere. The outlet of the exhaust system is a demarcation point-upstream the captured mass is the operator or building owner's concern, whereas downstream into the atmosphere, it affects air quality. Building codes have long required operators to deal with the upstream section. More recently, regulations are being placed on what kitchens can emit to the atmosphere. The industry is responding to this challenge with product innovations. Recently gained understanding of cooking emissions supports much of the innovation-but not all. This paper evaluates the purported benefit of adding better filtration and ultraviolet C (UVC) bulbs in kitchen hoods. A "UV hood" claims a two-step process to reduce emissions: better filters capture more emitted mass, and UVC photons and ozone drive photo-decomposition and oxidation reactions of some of the remaining greasy constituents. Adding UV to a hood at least doubles the cost compared to an equivalent non-UV hood. There is evidence that UV hoods do reduce some emissions. The essential question is whether improved performance is due to UV or relatively inexpensive, improved filters. Experimentation exposed an oleic acid aerosol, representative of cooking emissions, to UVC energy and ozone at higher concentrations and for longer exposure times than can occur in a UV hood. Particle-size and chemical changes were measured on samples collected with UV bulbs off and on. Results strongly indicate little change is happening and most emission reductions are caused by better filtration and not UV. The conclusion is that UV hoods fall short of claimed performance, and unreacted ozone may increase air pollution.

Population-based surveys on the frequency of common skin diseases in adults--is there a risk of response bias?

Population-based surveys on the frequency of common skin diseases are important in determining the health needs of a community. As they rely on voluntary presentation, there is a risk of response bias which may compromise the quality of the data obtained. The aim was to determine in what way and to what degree response bias may occur in a population-based survey on the frequency of common skin diseases in adults. A follow-up study was conducted on 1043 out of 2500 adults who did not attend for examination as part of a randomized population-based survey on the frequency of common skin diseases amongst adults in Maryborough, Central Victoria, Australia. Nonrespondents were more likely to be at the extremes of age, retired, unemployed and less likely to report that they had a history of skin disease than the respondents. Subsequent examination of a sample of the nonrespondents revealed they were more likely to have skin cancers and Campbell de Morgan angiomas than the respondents. These differences cannot be fully explained on the basis of an age-related response bias alone. Response bias is a risk in population-based surveys of common skin diseases which rely on voluntary presentation. Some attempt should be made to sample the nonrespondents in these surveys to determine the nature and extent of any bias and to adjust for it, if necessary.

The prevalence of common skin conditions in Australian school students: 4 Tinea pedis.

Tinea pedis is a condition that is common, often undiagnosed and frequently inadequately treated. It is reported as being rare in young children, but there are relatively few population-based reports of prevalence. A randomized sample of 2491 students from schools throughout the State of Victoria, Australia, were examined by dermatologists and dermatology registrars, who recorded clinical signs suggestive of tinea pedis, which were then confirmed by fungal culture. The age- and sex-adjusted prevalence of culture-proven tinea pedis was 5.2% [95% confidence interval (CI) 3.58-6.82] increasing with age from 2.1% (95% CI 0.95-3.28) in 4-6 year olds to 9.7% (95% CI 5.21-14.26) in 16-18 year olds. A higher proportion of males (6.0%) had tinea pedis than females (4.3%). Trichophyton mentagrophytes and T. rubrum were the most common dermatophytes isolated on culture. Less than 40% of those with a positive diagnosis had reported on the questionnaire that they had tinea. Of those who reported correctly that they had tinea, 75% had used one or more products to treat their condition, of which more than 40% were classified as unlikely to have any therapeutic effect on tinea pedis. These data confirm that tinea pedis, a potentially transmissible disease, is common in Australian schoolchildren, including those in primary school. There is a need for education programmes in schools on the nature of tinea pedis, the treatment available, and the public health approach to infection control within the school and home environment.

The prevalence of common skin conditions in Australian school students: 2. Atopic dermatitis.

The prevalence of atopic dermatitis (AD) was recorded following examination by dermatologists and dermatology registrars of a random sample of 2491 school students throughout the State of Victoria, Australia. The overall prevalence, based on clinical examination, was 16.3% (95% confidence interval, CI 14.1-18.5), being higher in girls (17.7%; 95% CI 15.0-20.4) than boys (14.8%; 95% CI 11.8-17.8). Using the U.K. Working Party Diagnostic Criteria for AD reduced the prevalence to 10.8% (95% CI 9.3-12.3) with the prevalence in girls 12.3% (95% CI 10.1-14.4) and in boys 9.2% (95% CI 7.1-11.4). The prevalence was highest in 4-6 year olds (18.7% on clinical examination, 11.5% using the U.K. Working Party Criteria), decreasing with increasing age to 11.6% on clinical examination (8. 6% on U.K. Working Party Criteria) among 16-18 year olds. Most of those with AD were classified as having mild disease (54.1%), with 32.1% classified as having minimal and 13.8% as having moderate to severe disease. Over 80% of those who reported on the questionnaire that they had dermatitis that was then confirmed on examination had been using one or more products to treat it. Nearly 90% of these products were classified as efficacious, with medical practitioners being the major source of advice for their use (77%). Pharmacists (8%), family/friends (6%) and others (9%), including beauticians and naturopaths, made up the remainder of the persons from whom those affected had sought advice about their treatment. These data, the first community-based prevalence data on AD published from Australia, confirm that the condition is common among those of school age. There is a need for AD to be included among those conditions that are discussed in health education lessons in schools.

The frequency of common nonmalignant skin conditions in adults in central Victoria, Australia.

BACKGROUND: Nonmalignant skin conditions are believed to be common in adults, although there are very few community-based studies to determine their exact frequency. OBJECTIVE: To record the prevalence of common, nonmalignant skin conditions in adults in central Victoria, Australia. METHODS: A total of 1457 respondents from a random selection of adults aged 20 years and over from Maryborough, central Victoria, were given a total body examination by a dermatologist or dermatology trainee. People with any nail or skin signs suggestive of tinea had scrapings taken for fungal culture. RESULTS: The age- and sex-adjusted prevalence of warts was 7.1% (95% confidence interval (CI), 5.8-8.4%), acne 12.8% (95% CI, 11.0-14.5%), atopic dermatitis 6.9% (95% CI, 5.6-8.3%), seborrheic dermatitis 9. 7% (95% CI, 8.2-11.2%), asteatotic dermatitis 8.6% (95% CI, 7.1-10. 0%), psoriasis 6.6% (95% CI, 5.7-7.9%), culture-positive tinea 12% (95% CI, 10.3-13.6%), seborrheic keratoses 58.2% (95% CI, 55.6-60. 7%), and Campbell de Morgan spots (cherry angiomas) 54.4% (95% CI, 51.9-57.0%). There was variation in the prevalence of many of these conditions with age. CONCLUSIONS: This study demonstrates that nonmalignant skin conditions are common in adults in Australia. Their diagnosis and management represent a considerable burden not only to those suffering from the conditions, but also to the health system which provides for their care.

The prevalence of common skin conditions in Australian school students: 1. Common, plane and plantar viral warts.

Although viral warts are common, their exact frequency in the community is often underestimated and not well recorded. A random sample of 2491 students from schools throughout the State of Victoria, Australia were examined by dermatologists and dermatology registrars to record the prevalence of common, plantar and plane warts. The overall prevalence of warts adjusted for the age and sex of Victorian school children was 22% (95% confidence interval (CI) 20.1-20.7) varying from 12% (95% CI 9.4-15.7) in 4-6 year olds to 24% (95% CI 18.3-30.4) in 16-18 year olds. Common warts were the most frequent (16%) compared with plantar warts (6%) and plane warts (2%). There was no difference in the overall frequency of warts between males and females and there was no difference in frequency between those who had eczema and those who did not. Almost 40% of those found to have warts on examination had indicated on the survey questionnaire that they did not have any of these lesions. Of those who knew that they had warts, only 38% had used any treatment for them. These data, the first community-based prevalence data on warts ever published from Australia, confirm that warts are indeed common. They suggest the need for education programmes in schools on the nature of these lesions and the treatment available.

The prevalence of common skin conditions in Australian school students: 3. acne vulgaris.

The prevalence, severity and disability related to facial acne (comprising acne on the head and neck) was assessed in a randomized sample of 2491 students (aged 4-18 years) from schools throughout the State of Victoria in Australia. Students were diagnosed clinically by a dermatologist or dermatology registrar. The overall prevalence (including 4-7 year olds) was 36.1% (95% confidence intervals, CI 24.7-47.5), ranging from 27.7% (95% CI 20.6-34.8) in 10-12 year olds to 93.3% (95% CI 89.6-96.9) in 16-18 year olds. It was less prevalent among boys aged 10-12 years than girls of the same age; however, between the ages of 16 and 18 years, boys were more likely than girls to have acne. Moderate to severe acne was present in 17% of students (24% boys, 11% girls). Comedones, papules and pustules were the most common manifestations of acne, with one in four students aged 16-18 years having acne scars. Twelve per cent of students reported a high Acne Disability Index score. This tended to correlate with clinical severity, although there was some individual variation in perception of disability. Seventy per cent of those found to have acne on examination had indicated in the questionnaire that they had acne. Of those, 65% had sought treatment, a substantial proportion of which (varying with who gave the advice) was classified as being likely to have no beneficial effect. This is the first population-based prevalence study on clinically confirmed acne published from Australia. The results show that acne is a common problem. They suggest the need for education programmes in schools to ensure that adolescents understand their disease, and know what treatments are available and from whom they should seek advice.