RESUMO
To date, in many countries the only legally valid method for evaporative cooling system (ECS) monitoring is the culture method. However, a duration of up to 14â¯days and a risk of underestimation of Legionella concentrations are seen as limitations of cultivation methods. Rapid cultivation-independent methods are an important step towards a more practicable monitoring of ECS to quickly control interventions if elevated concentrations of Legionella are found. Two commercial kits for quantitative polymerase chain reaction (qPCR) and viability-qPCR (v-qPCR) were studied, comprising sample filtration and DNA extraction. Cryopreserved Legionella pneumophila were established as calibration standard with intact (ILC) and total Legionella count (TLC) determined by flow cytometry before conducting spiking experiments in commercial mineral water and artificial process water. Final assessment was carried out using real ECS samples. Recovery and robustness ranged from 86 to 108â¯% for qPCR with a drop to 40-60â¯% for v-qPCR when compared to direct extraction, possibly attributable to cell damage during sample concentration. All methods including culture did perform well regarding linearity with R2â¯≥â¯0.95 for most trials. Detected concentrations in comparison to spiked Legionella counts differed with culture averaging 25⯱â¯7â¯% of spiked ILC and v-qPCR being closest to spiked concentrations with 65-144â¯%. In comparison, qPCR was several fold above spiked TLC concentrations. For real ECS samples Legionella spp. were detected in concentrations above 103 GU/100â¯mL by v-qPCR in 70-92â¯% of samples, depending on the kit used. Most of these samples were either culture-negative or not evaluable on agar plates. This study showed that a cryopreserved bacterial standard based examination is applicable and can be used for future v-qPCR verification. For assessment of differences in results between culture and v-qPCR/qPCR in ECS samples expert knowledge about the operating mode and used analytical methods is required. Guidelines addressing this issue could be a solution.
RESUMO
Background and Objectives: Exposure to recreational noise is becoming increasingly important due to a change in leisure behavior amongst children and adolescents. The aim of this pilot study was to assess exposure of 6th grade pupils to recreational noise from portable listening devices (PLD). Furthermore, preventive measures to reduce recreational noise exposure should be identified. Methods: In "Ohrkan Kids", 38 Bavarian pupils aged 11 to 14 were interviewed regarding their music listening behavior using a standardized questionnaire. In addition, measurements of commonly used volume settings on the children's portable listening devices were carried out. Furthermore, the German Social Accident Insurance (DGUV), health insurance companies as well as health and education ministries of the German federal states were surveyed regarding their activities in the prevention of recreational noise exposure. Results: Based on the questionnaire data for weekly usage, 10 out of 31 children (32.3%) exceeded the upper exposure value of 85 dB recommended by labor protection law. Taking actually measured values, 9 out of 31 children (29%) exceeded this level. The DGUV and some federal states carry out specific projects for the prevention of recreational noise exposure. Conclusion: The large number of children with hazardous music consumption indicates that measures for the prevention of noise-induced hearing loss are already required for 11 to 14 year olds. To maximize the number of children addressed, age-appropriate and target-group-specific preventive measures are needed. As there are only few studies which examined the effectiveness of awareness campaigns for the prevention of recreational noise, any future prevention projects should be evaluated with an increased focus on estimating their effectiveness.
Assuntos
Exposição Ambiental/prevenção & controle , Exposição Ambiental/estatística & dados numéricos , Perda Auditiva/epidemiologia , Perda Auditiva/prevenção & controle , Ruído/efeitos adversos , Recreação , Estudantes/estatística & dados numéricos , Adolescente , Criança , Exposição Ambiental/análise , Feminino , Alemanha/epidemiologia , Humanos , Masculino , Música , Projetos Piloto , Prevalência , Fatores de RiscoAssuntos
Microbiologia do Ar/normas , Poluição do Ar em Ambientes Fechados/prevenção & controle , Exposição Ambiental/prevenção & controle , Monitoramento Ambiental/normas , Pneumopatias Fúngicas/diagnóstico , Pneumopatias Fúngicas/prevenção & controle , Poluição do Ar em Ambientes Fechados/análise , Exposição Ambiental/análise , Fungos/isolamento & purificação , Alemanha , Humanos , Pneumopatias Fúngicas/microbiologia , Guias de Prática Clínica como AssuntoRESUMO
BACKGROUND: Bioaerosol pollution of workplace and home environments mainly affects airways and mucous membranes. The effect of environmental outdoor residential bioaerosol pollution, for example, livestock holdings, farming, and waste disposal plants, is unclear. AIMS: To investigate the perceived health of residents living in areas with measurable outdoor bioaerosol pollution (for example, spores of Aspergillus fumigatus and actinomycetes), and effects of accompanying odours. METHODS: In a cross sectional study, double blinded to ongoing microbial measurements, doctors collected 356 questionnaires from residents near a large scale composting site, and from unexposed controls in 1997. Self reported prevalence of health complaints during the past year, doctors' diagnoses, as well as residential odour annoyance were assessed. Microbiological pollution was measured simultaneously in residential outdoor air. RESULTS: Concentrations of >10(5) colony forming units of thermophilic actinomycetes, moulds, and total bacteria/m(3) air were measured 200 m from the site, dropping to near background concentrations within 300 m. Positive adjusted associations were observed for residency within 150-200 m from the site versus unexposed controls for self reported health complaints: "waking up due to coughing", odds ratio (OR) 6.59 (95% confidence interval (CI) 2.57 to 17.73); "coughing on rising or during the day", OR 3.18 (95% CI 1.24 to 8.36); "bronchitis", OR 3.59 (95% CI 1.40 to 9.4); and "excessive tiredness", OR 4.27 (95% CI 1.56 to 12.15). Reports of irritative airway complaints were associated with residency in the highest bioaerosol exposure, 150-200 m (versus residency >400-500 m) from the site, and period of residency more than five years, but not residential odour annoyance. Lifetime prevalence of self reported diseases did not differ with exposure. CONCLUSIONS: Bioaerosol pollution of residential outdoor air can occur in concentrations found in occupational environments. For the first time residents exposed to bioaerosol pollution were shown to report irritative respiratory complaints similar to mucous membrane irritation independently of perceived odours.