Giorgio Gilli

Concentrations of nitrates in drinking water and incidence of gastric carcinomas: first descriptive study of the Piemonte Region, Italy.

A descriptive epidemiological research, within the Piemonte Region was carried out, to consider whether there is an association between concentrations of nitrates in drinking water and the incidence of gastric carcinomas. The results indicate that an association does exist, but also that concentrations of nitrates higher than 20 mg/l in drinking water are a risk factor for people exposed.

Analysis of environmental endocrine disrupting chemicals using the E-screen method and stir bar sorptive extraction in wastewater treatment plant effluents

Endocrine disrupting chemicals (EDCs) have become a major issue in the field of environmental science due to their ability to interfere with the endocrine system. Recent studies show that surface water is contaminated with EDCs, many released from wastewater treatment plants (WWTP). This pilot study used biological (E-screen assay) and chemical (stir bar sorptive extraction-GC-MS) analyses to quantify estrogenic activity in effluent water samples from a municipal WWTP and in water samples of the recipient river, upstream and downstream of the plant. The E-screen assay was performed on samples after solid phase extraction (SPE) to determine total estrogenic activity; the presence of estrogenic substances can be evaluated by measuring the 17-beta-estradiol equivalency quantity (EEQ). Untreated samples were also assayed with an acute toxicity test (Vibrio fischeri) to study the correlation between toxicity and estrogenic disruption activity. Mean EEQs were 4.7 ng/L (+/-2.7 ng/L) upstream and 4.4 ng/L (+/-3.7 ng/L) downstream of the plant, and 11.1 ng/L (+/-11.7 ng/L) in the effluent. In general the WWTP effluent had little impact on estrogenicity nor on the concentration of EDCs in the river water. The samples upstream and downstream of the plant were non-toxic or weakly toxic (0<TU<0.9) while the effluent was weakly toxic or toxic (0.4<TU<7.6). Toxicity and estrogenic activity were not correlated. At most sites, industrial mimics, such as the alkylphenols and phthalates, were present in higher concentrations than natural hormones. Although the concentrations of the detected xenoestrogens were generally higher than those of the steroids, they accounted for only a small fraction of the EEQ because of their low estrogenic potency. The EEQs resulting from the E-screen assay and those calculated from the results of chemical analyses using estradiol equivalency factors were comparable for all samples and closely correlated.

Occupational exposure to formaldehyde and biological monitoring of Research Institute workers

AIM The aim of this study was to verify the presence of a relationship between formaldehyde exposure in the work environment with biological markers of exposure and of effect. METHODS Exposure to formaldehyde (FA) of 36 workers in different laboratories of a Cancer Research Institute and biomarkers of exposure, such as formaldehyde human serum albumin conjugate (FA-HSA) and biomarkers of effect, such as chromosome aberration (CA), micronuclei (MN) and sister chromatid exchanges (SCEs) were measured in peripheral blood lymphocytes of the same workers. RESULTS Individual FA levels of exposure ranged from 4.9 microg/m(3) to 268.7 microg/m(3). Subjects with high FA exposure showed a significant increase of the biomarker of exposure FA-HSA, but biomarkers of effect did not show any significant differences. CONCLUSIONS A significant relationship was observed between occupational exposure to FA and a biological marker of exposure (FA-HSA). The markers of effect used (CA, MN and SCE) failed to indicate the presence of genetic damage.

Ambient Air Levels and Occupational Exposure to Benzene, Toluene, and Xylenes in Northwestern Italy

The purpose of this study was to determine benzene, toluene, and xylenes air pollution in two cities in Italy (Biella and Torino) having different traffic intensities and to investigate whether new environmental conditions occurred consequent to the changes of gasoline composition in Europe during the last 20 yr. Furthermore, three types of urban occupational exposure (petrol pump attendants, traffic policemen, and municipal employees) to the same hydrocarbons were compared to verify three different expected levels of exposure. Results in Biella demonstrate a direct relationship between traffic density and level of human exposure to these pollutants. Air concentrations for benzene were 2.3 w g/m 3 in a suburban area having low traffic and 10.3 w g/m 3 in the central area having high traffic. The comparison to trend analysis recently carried out in Torino indicates it is possible to improve the situation in the central area of Biella by adopting the same traffic limitations imposed in Torino. Personal sampling devices demonstrated that only the petrol pump attendants show, by means of a multivariate analysis, statistically significant higher levels of benzene compared to the other two professional categories, in both winter and summer. Values found in the present study for petrol pump attendants were around 1 mg/m 3 . Environmental and occupational exposure to benzene, toluene, and xylenes could be largely lowered by adopting preventive measures including traffic restrictions, the reduction of aromatic chemical content in gasoline, and the recovery of gasoline vapors at petrol pump stations.

The endocrine disrupting activity of surface waters and of wastewater treatment plant effluents in relation to chlorination

The present study investigated the biological quantification of estrogenic activity in the effluent of a wastewater treatment plant (WWTP) and in the recipient river in north-western Italy. Samples of the WWTP effluent and those of river water upstream and downstream the WWTP were taken from September 2006 to May 2007. The effluent was evaluated in the presence and absence of chlorination. The E-screen assay, with human estrogens receptor-positive MCF-7 BUS breast cancer cells, was performed on samples after solid-phase extraction to determine the total estrogenic activity by measuring the 17beta-estradiol equivalent quantity (EEQ). In order to study the correlation between estrogenicity and toxicity, untreated samples were also assayed with the acute toxicity test Microtox. Furthermore, to determine the efficiency of the chlorination process, all the samples were analysed for disinfection by-products (trihalomethanes) and Escherichia coli. The mean EEQs were 5.0 ng/L (+/-6.1 ng/L) upstream of the plant, 6.7 ng/L (+/-7.4 ng/L) downstream from the plant and 23.3 ng/L (+/-20.4 ng/L) in the WWTP effluent. The difference between upstream and downstream of the treatment plant was not significant. Chlorinated water samples had lower estrogenic activity and E. coli concentrations, but had greater toxicity and higher trihalomethane concentrations. Estrogenic activity was not correlated with toxicity. These results suggest that the WWTP effluent had little impact on the estrogenic activity of the recipient river.

Application of a real-time qPCR method to measure the methanogen concentration during anaerobic digestion as an indicator of biogas production capacity

Biogas is an energy source that is produced via the anaerobic digestion of various organic materials, including waste-water sludge and organic urban wastes. Among the microorganisms involved in digestion, methanogens are the major microbiological group responsible for methane production. To study the microbiological equilibrium in an anaerobic reactor, we detected the methanogen concentration during wet digestion processes fed with pre-treated urban organic waste and waste-water sludge. Two different pre-treatments were used in successive experimental digestions: pressure-extrusion and turbo-mixing. Chemical parameters were collected to describe the process and its production. The method used is based on real-time quantitative PCR (RT-qPCR) with the functional gene mcrA as target. First, we evaluated the validity of the analyses. Next, we applied this method to 50 digestate samples and then we performed a statistical analysis. A positive and significant correlation between the biogas production rate and methanogen abundance was observed (r = 0.579, p < 0.001). This correlation holds both when considering all of the collected data and when the two data sets are separated. The pressure-extrusion pre-treatment allowed to obtain the higher methane amount and also the higher methanogen presence (F = 41.190, p < 0.01). Moreover a higher mean methanogen concentration was observed for production rate above than of 0.6 m(3) biogas/kg TVS (F = 7.053; p < 0.05). The applied method is suitable to describe microbiome into the anaerobic reactor, moreover methanogen concentration may have potential for use as a digestion optimisation tool.

Involuntary Exposure to Tobacco Smoke in Adolescents: Urinary Cotinine and Environmental Factors

The relationship between environmental tobacco smoke exposure and urinary cotinine was studied in 434 14-y-old schoolchildren. To estimate the independent contribution of physiological and environmental variables to cotinine concentrations, we conducted a multiple regression analysis of log-transformed cotinine (R(2) = .21, p < .0001). Environmental tobacco smoke exposure was associated with sharing a household with members who smoked. The most profound associations were linked to (a) the smoking habits of the mother (beta = 5.135, p = .0397); (b) the combined smoking habits of the mother and other family members (beta = 8.201, p = .0020); and (c) the total number cigarettes smoked each day by family members in the household (beta = 0.217, p = .0008). Passive smoke exposure of adolescents is a preventable risk that could be reduced by improving ventilation and by increasing the living space available to each family member. Parents should avoid smoking at home in the presence of their children.

BIOLOGICAL DRINKING WATER TREATMENT PROCESSES, WITH SPECIAL REFERENCE TO MUTAGENICITY

Many researches have demonstrated that the use of biological processes in the production of drinking water has many advantages over conventional alternatives. One possibility is that biological processes will result in lower levels of genotoxic by-products in the drinking water. This possibility was investigated in the present study, which compares the levels of such by-products following either chemical or biological treatments. Water samples, collected at the main steps of the two key stages of both treatments were passed over XAD2/8 resins, to concentrate micropollutants, included by-products, for subsequent analysis using the microsome/Salmonella assay (TA98 and TA100±S9). The results showed that biological treatment, avoiding break-point chlorination, limits by-product formation and associated mutagenic generation. It follows that, in this respect, biological processes seem to have significant advantages over conventional water treatments.

Mutagenic properties of PM2.5 urban pollution in the Northern Italy: the nitro-compounds contribution.

PM2.5 is the breathable fraction of the particulate matter and some adverse health effects, such as respiratory functionality, cardiological diseases and cancer, can be in some measure attributable to this risk factor exposure. Some of the most carcinogen compounds transported by PM2.5 are nitro-compounds. In this study, a strengthened in vitro bioassay--able to predict the mutagenic/carcinogenic activity of the environmental mixtures--was conducted on PM2.5 organic extracts to define the nitro-compounds burden. PM2.5 air pollution was daily monitored, during 2006, in three cities located in the Northern part of Italy (Torino, Pavia and Verona) and the mutagenic properties of the PM2.5 organic extracts were assessed with the Ames test. The bacterial used in this study were three Salmonella typhimurium strains: TA98, nitroreductase-less mutant TA98NR and YG1021 carrying a nitroreductase-producing plasmid. The annual PM2.5 mean level measured in Torino was 46.5 (+/-31.6) microg/m(3), in Pavia 34.8 (+/-25.1) microg/m(3), and in Verona 37.3 (+/-27.8) microg/m(3), while the mutagenicity expressed as TA98 net reverants/m(3) was 28.0 (+/-22.1), 28.3 (+/-24.9), and 34.2 (+/-30.9) respectively. Monthly pool bioassays, conducted with the three different strains, showed a greater mutagenic response of the YG1021 in each city. The relationship among the mutagenic answers for YG1021:TA98:TA98NR was about 6:3:1 (p<0.001). Over nitroreductase activity enhanced the response of 2.2, 2.0 and 1.7 times for Torino, Pavia, and Verona (ANOVA Torino p<0.05) respectively. Without nitroreductase activity the genotoxicity was limited. These biological findings are able to describe a relevant role played by the nitro compounds in the mutagenic properties of the urban PM2.5 in the Padana plain; moreover the bacterial nitroreductase plays a predominant role in DNA interaction primarily for Torino PM2.5 extracts.

The role of different methanogen groups evaluated by Real-Time qPCR as high-efficiency bioindicators of wet anaerobic co-digestion of organic waste

Methanogen populations and their domains are poorly understood; however, in recent years, research on this topic has emerged. The relevance of this field has also been enhanced by the growing economic interest in methanogen skills, particularly the production of methane from organic substrates. Management attention turned to anaerobic wastes digestion because the volume and environmental impact reductions. Methanogenesis is the biochemically limiting step of the process and the industrially interesting phase because it connects to the amount of biogas production. For this reason, several studies have evaluated the structure of methanogen communities during this process. Currently, it is clear that the methanogen load and diversity depend on the feeding characteristics and the process conditions, but not much data is available. In this study, we apply a Real-Time Polymerase Chain Reaction (RT-PCR) method based on mcrA target to evaluate, by specific probes, some subgroups of methanogens during the mesophilic anaerobic digestion process fed wastewater sludge and organic fraction of the municipal solid waste with two different pre-treatments. The obtained data showed the prevalence of Methanomicrobiales and significantly positive correlation between Methanosarcina and Methanosaetae and the biogas production rate (0.744 p < 0.01 and 0.641 p < 0.05). Methanosarcina detected levels are different during the process after the two pre-treatment of the input materials (T-test p < 0.05). Moreover, a role as diagnostic tool could be suggested in digestion optimisation.