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).

[Guides to chemical risk assessment in the construction industry]. / Percorsi di valutazione del rischio chimico in edilizia.

The presence of chemical agents in construction is certainly relevant in terms of quality, quantity and toxicity. Their manipulation can result in potential exposure as inhaled and/or through the skin. It is therefore possible and necessary to identify a list of substances to be considered relevant for the risk assessment and the possible environmental monitoring to verify the adequacy of the estimate made. The many variables inherent in construction make it extremely difficult to apply the usual methods of the industrial hygiene because it would not very significant conclusions in terms of space-time representation. SIMLII in one of its guidelines have proposed a "indexes" method that can provide useful information to the figures of prevention for the actions of their competence. The subsequent introduction of the REACH Regulation and exposure scenarios may help to further sharpening the assessment of chemical hazards in construction.

[Exposure assessment to chemical agents: algorithms and measurements; advantage and critical state]. / Valutazione dell'esposizione ad agenti chimici: algoritmi e misurazioni, vantaggi e criticità.

The exposure assessment to chemical agents may be worked out by "preliminary evaluation" on documentary examination to "instrumental measurements" through "algorithms application" or "screening measurements"; in the last years the need of dermal exposure assessment has increased. The application of the procedures has highlighted the need to distinguish between small and great plants, production processes, etc. and to "interpret" the rules. The paper, through the critical examination of the difficulties observed in these years of application of the risk assessment procedures, suggests some reflections upon the best management of the process of exposure assessment to chemical agents: from the preliminary evaluation to the instrumental measurements.

Micro-organisms and dust exposure in an Italian grain mill.

AIMS: In order to assess possible occupational risk for workers in a grain mill, we evaluated aerial microbiological contamination in different areas of the mill and at different points of the production line. We also measured the concentration of aerodispersed dust particles. METHODS AND RESULTS: An assessment of microbiological contamination levels based on a Global Index of Microbial Contamination per cubic metre (GIMC per m3), an Index of Mesophilic Bacterial Contamination, and an Amplification Index is proposed. The indices were obtained from total and fungal counts. The cleaning sector is the most contaminated area of the mill: the mean GIMC per m3 was 17,213.6. In this area, the average microbial contamination was 11.41 times higher than that in the external environment. The highest concentrations of aerodispersed dust (inhalable 2.763 mg m(-3); respirable 1.400 mg m(-3)) were found in the cleaning area. CONCLUSIONS: The proposed microbiological indices and the concentrations of aerodispersed dust particles show that the most hazardous section of the mill is the cleaning area. The large variation in the data does not depend on seasonal factors, but rather on not easily identifiable conditions of the internal environment which facilitate diffusion and/or proliferation of the micro-organisms. SIGNIFICANCE AND IMPACT OF THE STUDY: The proposed microbiological contamination indices and the evaluation of the concentration of dust particles allow the identification of critical positions during the production cycle so that suitable measures to prevent the aerial contamination can be taken.

House dust mites (Der p 1, Der f 1), cat (Fel d 1) and cockroach (Bla g 2) allergens in indoor work-places (offices and archives).

BACKGROUND: Exposure to indoor allergens has already been shown to occur in many public places, including workplaces, in several countries. Aim of this study was to measure the levels of house dust mites, cat and cockroach allergens in indoor workplaces (offices and archives) in Italy and to evaluate the possible relationships between allergen levels and building characteristics, type of ventilation, indoor relative humidity and temperature. METHODS: Der f 1 and Der p 1, Fel d 1, Bla g 2 were measured by ELISA in dust samples collected from floors or upholstered seats of 160 workplaces. RESULTS: Detectable Der p 1 levels were found in 86 (54%) workplaces Der f 1 in 87 (55%), Fel d 1 in 86 (54%) and Bla g 2 in 3 (1.9%). Der p 1 allergen concentrations expressed per weight were higher than the proposed sensitization thresholds in 7 samples, Der f 1 in 5, Fel d 1 in 6 and Bla g 2 in 3. The highest allergen levels were detected in samples from upholstered seats. A significant correlation was found between Der f 1 level on floors, expressed per surface, and indoor temperature (r = 0.39; P < 0.01). CONCLUSIONS: In our study we found that upholstered seats in workplaces in Italy may constitute a significant reservoir both of house dust mites and cat allergens. Exposure to these allergens in workplaces may represent a risk factor for elicitation of symptoms and/or induction/maintenance of inflammation in allergic individuals and might also constitute a risk factor for sensitization.

[Proposed microbiological indexes for the assessment of air quality in buildings]. / Proposta di indici microbiologici per la valutazione della qualità dell'aria degli edifici.

An assessment of biological risk in the workplace requires the measurement of microorganisms present in the air. Although it is currently difficult to establish a dose-response relationship on the basis of existing epidemiological data, the number and types of microorganisms present offer a useful index when evaluating the quality of the air. Using the results obtained from a study of 226 different offices located in buildings equipped with forced ventilation we propose an assessment of contamination levels based on a Global Index of Microbial Contamination/m3 (GIMC/m3). This index is calculated as the sum of the values of the total microbial count determined for mesophilic bacteria, psychrophilic bacteria and fungi in all sampled areas. GIMC/m3 fluctuates between a minimum value of 23 and a maximum value of 18.069: the mean value varies depending on the ventilation system mode setting, with a value of 145 when operating in the heating mode, 265 in the air-conditioning mode and 258 under simple forced ventilation. 95.5% of the offices under study had a GIMC/m3 value of below 1000: this value is proposed as a threshold limit above which a more extensive assessment of contamination levels based on the measurement of further microbiological indexes should be carried out. To this aim we propose an Index of Mesophilic bacterial Contamination (IMC), obtained by calculating the ratio between the CFU/m3 value measured for mesophilic and psychrophilic bacteria in the same sampling point. The measurement of the Amplification Index (AI) completes the evaluation and this is determined by calculating the ratio between the GICM/m3 values measured inside the building and those measured outside. When considering these observations as a whole we are able to classify the various work areas under study into groups and categories according to the observed values of the proposed microbial contamination indexes.

[The measurement of a benzene metabolite, urinary S-phenylmercapturic acid (S-PMA), in man by HPLC]. / Dosaggio di un metabolita del benzene l'acido S-fenilmercapturico urinario (S-PMA), nell'uomo, mediante HPLC.

Benzene is a widely used solvent, currently present in the industrial environment at concentrations in the order of ppm. A valid method of biological monitoring that is easy to perform is needed for assessing occupational exposures. Benzene is metabolized in the body by microsomal cytochrome P-450 mono-oxygenase system into benzene epoxide. Benzene epoxide is metabolized along three different pathways which end in the excretion of trans, trans muconic acid, S-phenyl-mercapturic (S-PMA) and different phenols. A new method has been developed to evaluate urinary S-PMA of subjects exposed to benzene. Human urine is acidified with HCl to PH 1 and passed through a Sep-Pak C18 cartridge. The cartridges are washed with diluted HCl and a mixture of water/methanol/acetic acid and then eluted with acidified chloroform. The eluate is dried and reconstituted with a buffer phosphate, then passed through an anionic exchange cartridge (SAX) which is washed with diluted buffer and diluted HCl. S-PMA is recovered by eluting with concentrated buffer and is transformed into S-phenyl-cysteine. Finally, S-phenyl-cysteine is detected by HPLC connected with a fluorescence detector (wavelengths: excitation 330 nm, emission 440 nm) after derivatization with o-phthalaldehyde (OPA) and 2-mercapto-ethanol (MCE). The detection limit of the method is about 0.5 micrograms/l, the recovery of S-PMA is 90.0% and the variation coefficient is 3.8%. The method was checked on urine samples of 8 male non-smokers and 10 smokers: median values of 1.3 and 9.2 micrograms/g creatinine respectively of S-PMA were obtained. A further analysis on urine samples of 66 occupationally exposed workers (smokers and non-smokers) revealed a median value of S-PMA of 46.6 micrograms/g creatinine, compared with a median environmental benzene exposure of 1.99 mg/m3. These results suggest that S-PMA can be regarded in the future as a useful indicator for monitoring individual and collective low-level benzene exposure.