Effectiveness of a combined UV-C and ozone treatment in reducing healthcare-associated infections in hospital facilities.

BACKGROUND: Hospital-acquired infections pose an ongoing threat to patient safety due to the presence of multi-drug-resistant organisms (MDROs) and other pathogens such as Clostridioides difficile which are dependent on thorough and effective cleaning and disinfection by personnel. METHODS: This study evaluated the influence of UV-C air treatment: the air in the room was sanitized by UV-C and redirected into the room. In addition, ozone was released into the room to treat actual surfaces in low-risk areas such as hospital gyms, and high- to medium-risk areas such as hospital rooms. To this aim, a portable device designed for treating the environment air was tested against nine bacterial strains including Aspergillus spp. and Clostridioides spp. RESULTS: The use of UV-C air treatment during daily operations and ozone treatment achieved at least a 2-log10 pathogen reduction except for Clostridioides spp. CONCLUSION: Effective prevention of C. difficile normally requires the use of combined approaches that include chemical compounds and disinfection agents whose toxicity can be harmful not only to patients but also to healthcare personnel. Thus, the proposed no-touch device may be evaluated in future research to assess the needed requirements for its possible and full implementation in hospitals.

[Measurement of chemical agents in metallurgy field: electric steel plant]. / Misura degli agenti chimici in ambito metallurgico: acciaieria elettrica.

The steel industry maintains its important position in the context of the Italian production involving thousands of workers. The iron and steel processes are divided into primary steel industry, production of intermediate minerals, and secondary steel, scrap from the production of semi-finished industrial and consumer sector (metal inserted into components and metal used for dissipative uses, primarily coatings) and industrial waste. The paper presents the results of environmental monitoring carried out in some electric steel plant for the measurement of airborne chemicals that characterize the occupational exposure of workers employed in particular area like electric oven, to treatment outside the furnace, continuous casting area. For the sampling of the pollutants were used both personal and in fixed positions samplers. The pollutants measured are those typical of steel processes inhalable dust, metals, respirable dust, crystalline silica, but also Polycyclic Aromatic Hydrocarbons (PAH), polychlorinated dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs).

[Assessment of exposure to cancerogenic aromatic hydrocarbon during controlled-access highways management activities]. / Valutazione dell'esposizione ad idrocarburi aromatici cancerogeni nell'attività di gestione autostradale.

The purpose of this study was an integrated assessment of exposure to benzene and Polycyclic Aromatic Hydrocarbons (PAH) in 29 workers employed to manage a controlled-access highways. A campaign was performed in summertime by environmental monitoring (active and passive airborne personal sampler), as well as by biological monitoring (urine samples of the beginning and of the end of daily shift, baseline after two days of vacation). The measured environmental levels did not differ from background environmental concentrations found in a metropolitan area (i.e. benzo[a]pyrene < 1 ng/m3; benzene < 5 mcg/m3), and the results of biological monitoring were in agreement and were compatible with extra-professional habits of the investigated subjects (1-hydroxipyrene 50-990 ng/g creatinine; unmetabolized benzene 15-2010 ng/I; t-t muconic acid < 4-222 mcg/g creatinine).

[Criteria and methods for the study of occupational exposure to antineoplastic agents]. / Criteri e metodi per lo studio dell'esposizione occupazionale a chemioterapici antiblastici.

Risk assessment for occupational exposure to antiblastic chemotherapeutic drugs (ACD) is carried out by means of environmental and biological monitoring. These practices are not widespread and furthermore their results are frequently difficult to interpret. This paper discusses some of the most important aspects of risk assessment for ACD and in particular for their exposure evaluation. The following guidelines are proposed: a) working rooms, working procedures, type and quantity of drugs, and preventive measures must be checked using a standardized scheme for collecting data: an example of a check list experimented in some Italian hospitals is presented; b) cyclophosphamide, 5-fluorouracil, and Pt coordination compounds have been identified as tracers of drug mixtures usually administered, and their determination is recommended both in environmental and biological samples; c) for a correct evaluation of exposure, ACD should be determined firstly on the contaminated surfaces or on work clothes and secondly in urine of workers; the measurement of ACD in air must be limited to well documented conditions of high exposure and the urinary mutagenicity tests should be avoided; d) the biological monitoring practices should be enhanced, in particular the determination of ACD adducts to proteins and nucleic acids as promising indicators of effective dose.

Correlation between PAH airborne concentration and PAH-DNA adducts levels in coke-oven workers.

In order to evaluate the correlation between peripheral blood leukocyte DNA adducts as an indicator of exposure to polycyclic aromatic hydrocarbons (PAH) and the airborne contamination of PAH at the work places, a survey of a cohort of coke-oven workers has been carried out. In each workplace, total and specific PAH airborne concentrations were measured. Among the job title groups, the highest proportion of subjects with levels of adducts above the detection limit and the highest mean value were observed in the door-operators. The correlation between median values of environmental benzo(a)pyrene concentration and mean values of adducts concentration support the fact that the maintenance workers group has a higher relative risk (RR) to have detectable level of PAH-adducts, which is estimated to be 1.84 for an increase of 1 micrograms/m3 of benzo(a)pyrene.

[Assessment of exposure to polycyclic aromatic hydrocarbons in 3 work activities using mineral oils]. / Valutazione dell'esposizione a idrocarburi aromatici policiclici in tre attività lavorative che utilizzano olii minerali.

The exposure to polycyclic aromatic hydrocarbons (PAH) in different industries using cutting, hardening and extruding oils, was investigated determining their concentration in oils and in environmental samples. The following compounds: phenanthrene, anthracene, fluoranthene, pyrene, benzo-a-anthracene, chrysene, triphenylene, benzo-a-pyrene, benzo-e-pyrene and perylene were evaluated by means of gas-chromatography-mass spectrometry. PAH concentrations in oils ranged from 652 to 4461 ng/gr and environmental concentrations from 63.86 to 120.54 ng/mc. In particular the BaP concentrations varied from 0.73 to 1.9 ng/mc. These results, compared with those measured in other environmental surveys and with the limit values proposed in various countries, point out the existence of a very low inhalatory risk of PAH.

Biological monitoring of human exposure to coal tar. Urinary excretion of total polycyclic aromatic hydrocarbons, 1-hydroxypyrene and mutagens in psoriatic patients.

Three methods for the biological monitoring of human exposure to coal tar were compared. Levels of 1-hydroxypyrene(1-OH PYR), polycyclic aromatic hydrocarbons (PAH) and mutagens (Ames plate incorporation assay using Salmonella typhimurium strain TA98 in the presence of S9 and beta-glucuronidase) were determined in urinary samples from psoriatic patients undergoing topical treatment with mineral coal tar. A single sample of urine with a high content of PAH was diluted with urine of nonexposed, non-smoking subjects in order to obtain nine samples with a decreasing content of PAh metabolites. Mutagenicity of the extracts was detectable down to the dilution corresponding to a content in 1-OH PYR of about 50 micrograms/g creatinine and total PAH of 7 micrograms/g creatinine. In a second phase the three indicators of exposure to PAH were compared in 16 urinary samples from four psoriatic patients. The total PAH levels determined by the acidic deconjugation/reduction method were confirmed to be nearly always lower than the corresponding levels of 1-OH PYR alone. Most of the extracts were mutagenic, however, some of the samples with a high content in PAh metabolites were not mutagenic. In all the urinary samples analyzed the excretion of 1-OH PYR was markedly greater than in control subjects. 1-OH PYR and urinary mutagenicity levels were well correlated. The present data suggest that both the determination of mutagenicity and 1-OH PYR in urine may be used to monitor occupational exposure to PAH, the latter method being cheaper and of greater specificity and sensitivity.

[Toxicological and analytical lists: chromium and its compounds]. / Schede tossicologiche e analitiche: cromo e composti.

The main aspects of occupational exposure to chromium and chromium compounds are surveyed. Special attention is paid to the toxic action of this metal at the different target organs. The nutritional aspect of CrIII is examined preliminarily, and data detailing the metal contents in water and food are provided. As far the different working processes that entail occupational exposure to chromium are concerned, hygienic and environmental problems are discussed while identifying the average environment exposure to the different chemical forms of chromium (CrIII, CrIV, soluble and not soluble), as a function of the worker's tasks, and the relevant human response (total human Cr). Different hygienic and environmental standards in force in various countries and applicable to chromium compounds are compared. Additional information is given on the main aspects of chromium metabolism (absorption, distribution, excretion), and on the prevailing toxic actions, with specific reference to cancerogenesis. As far as biologic monitoring of the exposed people is concerned, the significance of Cr-U as dose-exposure indicator is discussed, also in the light of a critical review of the reference values. The report describes a series of analytical methods for the identification of chromium in aqueous and biologic matrices. The problems connected with health monitoring and fitness for work are eventually covered.

Mutagenic activity and polycyclic aromatic hydrocarbon levels in urine of humans exposed to therapeutical coal tar.

The urinary mutagenicity and the excretion of polycyclic aromatic hydrocarbons (PAH) in three non-smoking male patients, treated for psoriasis with cutaneous applications of crude coal tar, were analysed. Mutagenicity of the urinary extracts was measured by the plate incorporation assay using Salmonella typhimurium strains TA 98 and TA 100 in the presence of liver S9 fraction from Aroclor-induced rats with or without beta-glucuronidase. After concentration, hydrolysis and reduction of the urine sample, PAH levels were measured by high resolution gas chromatography/mass spectrometry. Following cutaneous treatment with coal tar, the urine of all three subjects showed noticeable levels of PAH and/or metabolites and marked mutagenicity both on strain TA 98 and TA 100 in the presence of S9 fraction. The addition of beta-glucuronidase increased the mutagenicity of the urinary extracts, the maximum values being attained on strain TA 100 in the presence of both microsomal fraction and deconjugating enzymes. The mutagenicity of urinary extracts from subjects treated therapeutically with crude coal tar was correlated (r = 0.788, P less than 0.01) with the total PAH levels in their urine. The PAH excreted in urine were mainly low molecular weight compounds, while benzo[a]anthracene was present in scarce amounts and the excretion of benzo[a]pyrene did not increase following the cutaneous exposure to the crude coal tar.

Mutagenic activity and polycyclic aromatic hydrocarbon levels in urine of workers exposed to coal tar pitch volatiles in an anode plant.

The mutagenicity of urinary extracts and the excretion of PAH from workers occupationally exposed to coal tar pitch volatiles in an anode plant were analyzed. Mutagenicity of the urinary extracts was measured by means of the plate test using S. typhimurium strain TA 98. After concentration, hydrolysis and reduction of the urine samples, PAH levels were measured by high resolution gas chromatography/mass spectrometry. No significant difference was found in the mutagenicity of the urinary extracts of non-smokers occupationally exposed to PAH as compared with the controls. Low PAH concentrations were found in the urine of the exposed subjects, which lends further support to the negative results obtained with the Ames' test. The increase of urinary PAH excretion, in relation to occupational exposure, was mainly due to the less mutagenic, low molecular weight compounds.