Characterization and control of terpene emissions in Finnish sawmills.

This article describes an experimental study of terpene emission rates during fresh pine and spruce sawing and processing. Total terpene emission was determined by summing the product of the exhaust airflow rate and the mean concentration in the exhaust. Terpene concentrations were measured at fixed sampling points between the sawing lines. Terpene emission during pine sawing was found to be around 10 times greater than that during spruce sawing. The emission rates given here can be used to predict emission rates for various production rates. The predicted emission rates can be used in mass balance models to predict concentrations or required airflow rates to achieve the target concentration level.

Assessment of terpene levels and workers' exposure in sawmills with Long Path FTIR.

This study focuses on the assessment of airbone terpene levels in the saw shed of a sawmill. It describes results and practical aspects concerning the indoor use of a Long Path FTIR measurement technique that was primarily developed for emission monitoring in outdoor applications. The results from FTIR sampling are compared with results from personal adsorbent samples and a point monitoring PID instrument. The Long Path FTIR light path covered the entire length of the saw shed in the mill. This enabled measurement of real-time, path integrated concentrations along the beam path. The four monoterpenes alpha-pinene, beta-pinene, delta 3-carene, and limonene were identified along with ethanol. Quantification was achieved by using a classical least square evaluation software. The limit of detection of the individual terpenes was 1.5 mg/m3, or 0.27 ppm. The terpene levels in the sawmill fluctuated significantly and the average concentrations exceeded the Swedish 8-hour PEL (150 mg/m3, 25 ppm). Peak levels were recorded near the Swedish short-term exposure limit (300 mg/m3, 50 ppm). Results from simultaneous sampling with personal adsorbents, analyzed by GC, showed good agreement with the long path FTIR sampling (r = 0.98, n = 7). The FTIR application described is general in nature and offers a stable and convenient form for continuous monitoring over extended periods of times, and the conclusions drawn from this study may well be applied in other similar surveys.

Contact urticaria with anaphylactic reactions caused by occupational exposure to iridium salt.

This paper presents the case of a non-smoking and non-atopic male, exposed to iridium chloride at work, who developed respiratory tract symptoms and contact urticaria. Application of iridium salt to normal skin caused contact urticaria. An iridium chloride prick test showed a positive reaction and a scratch test produced anaphylactoid reactions. Platinum salt allergy was excluded through prick testing with hexachloroplatinate solution. There is no previous report describing a case where an individual has a positive prick test reaction to iridium salts and simultaneously a negative one to platinum salts. The results are interpreted as immediate-type hypersensitivity (Type I allergy?) to iridium salt. The route of sensitization was probably through the airways. Further testing showed that iridium salt allergy could persist for at least 18 months after exposure ceases. 14 employees at the same factory were prick tested with iridium and platinum salts with negative results. Prick testing is recommended as a method of first choice when investigating a person with suspected iridium salt allergy.