Suchergebnisse

Abstract
The overall aim of our research is to study chimney sweeps exposure to soot to be able to give recommendations on how to effectively reduce the exposure. To do this a suitable method to study soot exposure is required. In this study we use a new method to study the personal airborne exposure to soot measured as black carbon (BC). BC is measured with a AethLabs MA200 micro aethalometer with a flow rate of 100 mL/min and sampling time of 1 min. By using a direct-reading instrument we aim to identify variability in exposure levels during the workday, and potential work tasks contributing to elevated exposure to soot. The study includes 20 chimney sweeps performing black sweeping in Sweden and BC is measured for eight workdays for each individual. During these days individuals also fill out a diary of work tasks performed. To assess the value of the BC levels, airborne polycyclic aromatic hydrocarbon (PAH) is also measured with personal sampler for particulate- and gas phase PAH. PAH is measured in parallel with BC during one workday. Preliminary results show variability of BC levels between different individuals as well as different workdays for the same individual. We are also able to link BC levels with work tasks from the diaries. Significantly elevated PAH levels and especially the particle-bound PAHs, including the carcinogenic benzo(a)pyrene, were observed in most samples.

Abstract
Coal tar creosote, or creosote, is a by-product of the carbonization of coal to produce coke and has been used as a wood preservative since the late 19th century. Creosote is a mixture of many different compounds such as polycyclic aromatic hydrocarbons (PAH)s, phenols and cresols. Even though several PAHs are carcinogenic to humans, creosote is still used in impregnation of railway ties and electricity and telephone poles. Occupational exposure can occure from inhalation of creosote vapour or through skin contact. Dermal uptake is considered to be the most important route of exposure to PAHs. Even though the ratio between different PAHs may vary, measurements of 1-hydroxy-pyrene (1-HP) in urine is the common method for biological monitoring of occupational exposure to PAH. This study was conducted indoors in a facility where railroad switches are assembled with concrete or creosote impregnated wood ties. The aim of the study was to assess the workers´exposure to PAHs by (i) measuring PAH 16 in the breathing zone from whole shift samples, (ii) examining the dermal exposure of pyrene using a tape stripping technique, (iii) assessing the workers´ internal exposure by measuring 1-OHP in urine samples. The study show that during construction of railroad switches made from creosote impregnated ties workers get urinary levels of 1-OPH above the Biological Guidance Value during the work week. Dermal uptake seems to be the main route of exposure and preventive measures should be focused upon reducing the dermal exposure.
Speaker Biography
Pål Graff works as a Professor at the Norwegian National Institute of Occupational Health and Norwegian University of Life Sciences. His main research interests are exposure assessment and epidemiology.