[Exposure to volatile organic solvents in a group of carpentry craftsmen]. / Esposizione a solventi organici volatili in un gruppo di falegnamerie artigiane.

BACKGROUND: The wide use of volatile organic solvent-based products in wood carpentry and the possible effects of long-term exposure to low dose mixtures of these solvents prompted an investigation in a group of small enterprises. OBJECTIVES: The investigation aimed at estimating risk in wood carpentry work via assessment of exposure. METHODS: Exposure to solvents was studied in a group of 13 enterprises (selected from a group of 52), via personal samplings, both active and passive. The solvents to be examined were selected on the basis of the information contained in the technical-toxicity sheets of the products used in these factories. RESULTS: The results show an average exposure generally within the TLV-TWA recommended by the various industrial hygiene associations. However, considering the wide variability of the concentration values observed, the possibility that these limits might be exceeded in the long term cannot be excluded. Comparison of the results of active and passive samplings, showed a substantial similarity of the two systems, with evident advantages of the passive system, as far as ease of use, workers' acceptance and costs are concerned. CONCLUSIONS: The results of this study can be a useful reference for all those (employers, occupational physicians, technicians, workers' representatives) who are required to take preventive measures especially in cases where environmental investigations are hindered by technical difficulties or are not regularly used in evaluation systems.

[Exposure to wood dust in a group of carpentry craftsmen in secondary wood processing]. / Esposizione a polveri di legno in un gruppo di falegnamerie artigiane di seconda lavorazione del legno.

In order to evaluate the risk connected with wood dust exposure in millwork on a group of 13 craft industries, 74 area dust samplings and 74 personal dust samplings were made. In personal samplings both the total portion and the respirable fraction were calculated. Area samplings showed dust levels (average, standard deviation, fiducial limit, FLS95%) under ACGIH TLV-TWA for soft wood dust: TLV-TWA for hard wood was basically reached, and OTL levels gave evidence for high risk of exceeding TLV-TWA in the medium-long term. The exposure levels by personal samplings (average, standard deviation, fiducial limit, FLS95%) were clearly over TLV-TWA, both for hard woods and, although less clear, for soft woods. OTL levels gave evidence for a frankly unacceptable exposure condition in the medium-long term. Differences between average levels of total dust exposure (2.5 mg/m3) and respirable portion (2.3 mg/m3) were not statistically significant (p > 0.05) as well as the differences among the 4 groups of companies with homogeneous product activity (p > 0.05). In consideration of toxicological peculiarity of wood dust and carcinogenicity of wood manufacture as exposure circumstances classified in group 1 by IARC, the results show the need for prevention measures to reduce workers' exposure risk, by means of environmental improvement and better work organization, technological structures, individual attitudes and personal protection.

Auger electron spectroscopic studies of stainless-steel implants.

Auger electron spectroscopy together with scanning electron microscopy has been used to study the interface between stainless-steel implants and human tissue. The thickness and nature of the oxide layer on the implants have been found to depend on the location of the implants in the body. Before implantation, the oxide layer is about 50 A thick, consisting mainly of chromium oxide. For implants located in cortical bone the thickness of the interfacial oxide layer remains unaffected, while it increases by a factor of three to four on samples located in bone marrow. In both these cases calcium and phosphorus are incorporated in the oxides. Implants located in soft tissue have an interfacial oxide layer with a thickness of about one and one-half times that on an unimplanted sample. On these samples, calcium and phosphorus are not found, but occasionally sulfur is found in the oxide layer. All these samples originated from the oral region of the body; the reason for this finding, however, is not known at present time. The interactions between the implants and human tissues resulting in the observed changes of the implant surfaces are discussed in terms of oxygen pressures and metabolic activity.