Olfactory dysfunction revisited: a reappraisal of work-related olfactory dysfunction caused by chemicals.

Occupational exposure to numerous individual chemicals has been associated with olfactory dysfunction, mainly in individual case descriptions. Comprehensive epidemiological investigations into the olfactotoxic effect of working substances show that the human sense of smell may be impaired by exposure to metal compounds involving cadmium, chromium and nickel, and to formaldehyde. This conclusion is supported by the results of animal experiments. The level of evidence for a relationship between olfactory dysfunction and workplace exposure to other substances is relatively weak.

Ototoxic substances at the workplace: a brief update.

Ototoxic chemicals can impair the sense of hearing and balance. Lately, efforts have been intensified to compile evidence-based lists of workplace agents with ototoxic properties. This article gives a rough overview of the latest relevant publications, which confirm that toluene, styrene, and lead should receive particular attention as ototoxic substances at the workplace. Moreover, there is sufficient evidence that occupational exposure to trichloroethylene, mercury, carbon monoxide, and carbon disulfide can affect the ear. Based on the existing information, industrial hygienists should make sure that occupational health professionals and the workforce are made aware of the risks posed by ototoxic substances; support their replacement or new technical measures to reduce exposure; make these substances a part of regular screening, develop tools that can early diagnose chemically induced hearing impairment, and investigate further into the ototoxic properties of these substances. Further research should focus on quantifying the combined effects of ototoxic substances and noise.

Sensory and pulmonary effects of acute exposure to sulfur dioxide (SO2).

BACKGROUND: Exposure to sulfur dioxide (SO(2)) affects large populations worldwide. Pulmonary effects have been reported at concentrations relevant in the general (<0.5 ppm) and working environment (>0.5 ppm). SO(2) is an irritant but the existing studies often emphasize only pulmonary effects and no clear dose-response relationship has yet been described. OBJECTIVES: Using a multi-level, multi-method approach, odor annoyance, sensory irritation and pulmonary effects of SO(2) were to be investigated in an experimental exposure study. METHODS: Eye blink frequency, rhinomanometry, spirometry and symptom ratings of acute health effects were assessed before, during, and after the exposures. Each session lasted 4h and concentrations of 0.5, 1, and 2 ppm were investigated and compared to a control condition using clean air. Sixteen human volunteers (8 females/8 males) participated and during exposure light physical exercise was simulated with bicycle ergometry. RESULTS: Eye blink frequency, nasal airflow, and lung function were not affected by the acute SO(2) exposure investigated. These physiological responses to moderate SO(2) exposures were not significantly affected by gender. Regarding subjectively measured chemosensory sensations, only odor annoyance ratings increased in a dose-dependent manner, but the average magnitudes were labeled weak to moderate. CONCLUSIONS: In healthy volunteers, without hyperresponsiveness to SO(2), no dose-dependent effects of acute SO(2) exposures up to 2 ppm could be measured. Due to olfactory perceptions subjects were aware of the different SO(2) exposures but the associated annoyance was relatively low.

Local lymph node assay (LLNA): comparison of different protocols by testing skin-sensitizing epoxy resin system components.

Thirteen epoxy resin system components were tested in the LLNA with regard to their sensitizing potency. Lymph node stimulation was quantified not only by measuring the incorporation of [3H]-thymidine into the ear lymph nodes but also the counts of cells recovered from these organs. Equivalent figures were obtained with both endpoints used for the evaluation of lymph node cell proliferation if the reference stimulation indices were adjusted. When dissolved in acetone, all test substances showed skin-sensitizing potential, mainly on the boundary between "strong" and "moderate" according to common potency evaluation schemes. Replacing acetone with acetone/olive oil (4:1) as a vehicle for four selected test items, resulted in considerably lower estimated concentrations for sensitization induction. The challenges in comparing the results obtained by different LLNA variations are discussed.

Commentary on "Penetration of benzene, toluene and xylenes contained in gasolines through human abdominal skin in vitro".

In this commentary we refer to the new data recently published by Adami et al. [Adami, G., Larese, F., Venier, M., Barbieri, P., Lo Coco, F., Reisenhofer, E., 2006. Penetration of benzene, toluene and xylenes contained in gasolines through human abdominal skin in vitro. Toxicol. In Vitro 20, 1321-1330], which we acknowledge as a reliable basis for the retrospective assessment of percutaneous benzene absorption at the workplace. The data from Adami et al. (2006) are supported by the literature and by a German approach for calculating the contribution of the dermal uptake of benzene to the total body burden. This knowledge is important for the judgment of leukaemia suspected to be an occupational disease.