Chemiluminescent fingerprints from airborne particulate matter: A luminol-based assay for the characterization of oxidative potential with kinetical implications.

In this study, a new chemiluminescent method based on the dependence of luminol light emission induced by free radicals in airborne particulate matter (PM) is proposed as a screening assay for the rapid characterization of samples from different sources based on their redox properties. This parameter is considered critical for assessing particulate matter toxicity and its impacts on human health. We propose a cell-free, luminescent assay to evaluate the redox potential of particulate matter directly on the filters employed to collect it. A joint chemometric approach based on Principal Component Analysis and Hotelling Analysis was applied to quickly sort out ambient particulate samples with a significantly different light emission profile caused by Luminol reaction. Based on Spearman correlation analysis, the association of the samples light emission intensity with their chemical composition and emission sources was attempted. The overall methodology was tested with certified reference materials and applied to two series of particulate matter samples previously subjected to thorough chemical speciation and subsequent source apportionment. The results show the effectiveness of the luminescent method, allowing the quick assessment of particulate matter oxidative potential, but providing further evidence on the complexity of the oxidative potential determination in this kind of samples. The chemometric processing of the whole dataset clearly highlights the distinct behavior among the two series of samples, the certificate standard reference materials, and the blank controls, supporting the suitability of the approach.

Unburned Tobacco Cigarette Smoke Alters Rat Ultrastructural Lung Airways and DNA.

INTRODUCTION: Recently, the Food and Drug Administration authorized the marketing of IQOS Tobacco Heating System as a Modified Risk Tobacco Product based on an electronic heat-not-burn technology that purports to reduce the risk. METHODS: Sprague-Dawley rats were exposed in a whole-body mode to IQOS aerosol for 4 weeks. We performed the chemical characterization of IQOS mainstream and we studied the ultrastructural changes in trachea and lung parenchyma of rats exposed to IQOS stick mainstream and tissue pro-inflammatory markers. We investigated the reactive oxygen species amount along with the markers of tissue and DNA oxidative damage. Moreover, we tested the putative genotoxicity of IQOS mainstream through Ames and alkaline Comet mutagenicity assays. RESULTS: Here, we identified irritating and carcinogenic compounds including aldehydes and polycyclic aromatic hydrocarbons in the IQOS mainstream as sign of incomplete combustion and degradation of tobacco, that lead to severe remodelling of smaller and largest rat airways. We demonstrated that IQOS mainstream induces lung enzymes that activate carcinogens, increases tissue reactive radical concentration; promotes oxidative DNA breaks and gene level DNA damage; and stimulates mitogen activated protein kinase pathway which is involved in the conventional tobacco smoke-induced cancer progression. CONCLUSIONS: Collectively, our findings reveal that IQOS causes grave lung damage and promotes factors that increase cancer risk. IMPLICATIONS: IQOS has been proposed as a safer alternative to conventional cigarettes, due to depressed concentration of various harmful constituents typical of traditional tobacco smoke. However, its lower health risks to consumers have yet to be determined. Our findings confirm that IQOS mainstream contains pyrolysis and thermogenic degradation by-products, the same harmful constituents of traditional cigarette smoke, and, for the first time, we show that it causes grave lung damage and promotes factors that increase cancer risk in the animal model.

Delta9-THC determination by the EU official method: evaluation of measurement uncertainty and compliance assessment of hemp samples.

Hemp cultivation is living a period of renewed interest worldwide after long years of opposition and abandonment. The European Union (EU) allows and subsidizes the growing of fiber and oilseed cultivars of Cannabis sativa L. with respect to the THC content limit of 0.2%. The EU method for the quantitative determination of Δ9-tetrahydrocannabinol (THC) content in hemp varieties provides to apply a tolerance of 0.03 g of THC per 100 g of sample concerning compliance assessment to that limit. However, the method does not report any precision data, especially useful as a function of THC content to evaluate measurement uncertainty and therefore to establish the conformity of hemp at different THC legal limits. Measurement uncertainty of the method by both bottom-up and top-down approach, besides repeatability and reproducibility, was investigated and estimated in the THC concentration range 0.2-1.0%, which includes the different legal limits set out for hemp around the world. We proposed Decision Rules for conformity of hemp showing that a non-compliant declaration beyond reasonable doubt should be stated when the THC content, as a mean result on a duplicate analysis, exceeds the limit by at least 11-15%, depending on THC limit. We highlighted other issues concerning practical aspects of hemp analysis, from sampling to evaluation of results, as well as the need to carry out collaborative studies on the EU method.

Glucocorticoids in Freshwaters: Degradation by Solar Light and Environmental Toxicity of the Photoproducts.

The photodegradation process of seven glucocorticoids (GCs), cortisone (CORT), hydrocortisone (HCORT), betamethasone (BETA), dexamethasone (DEXA), prednisone (PRED), prednisolone (PREDLO) and triamcinolone (TRIAM) was studied in tap and river water at a concentration close to the environmental ones. All drugs underwent sunlight degradation according to a pseudo-first-order decay. The kinetic constants ranged from 0.00082 min-1 for CORT to 0.024 min-1 for PRED and PREDLO. The photo-generated products were identified by high-pressure liquid chromatography coupled to electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS). The main steps of the degradation pathways were the oxidative cleavage of the chain 17 for CORT, HCORT and the rearrangement of the cyclohexadiene moiety for the other GCs. The acute and chronic toxicity of GCs and of their photoproducts was assessed by the V. fischeri and P.subcapitata inhibition assays. The bioassays revealed no significant differences in toxicity between the parent compounds and their photoproducts, but the two organisms showed different responses. All samples produced a moderate acute toxic effect on V. fisheri and no one in the chronic tests. On the contrary, evident hormesis or eutrophic effect was produced on the algae, especially for long-term contact.

The pursuit of good microbiological conditions in domestic softeners: a new improvement.

Effective resin disinfection is mandatory to ensure the microbiological quality of water treated by domestic softeners. The wet and sometimes warm environment inside the softener is ideal for bacteria growth. Our research was focused on the evaluation of the microbial quality of water from softeners sanitized by chlorine solutions or by electrolytic systems. We employed the heterotrophic plate count and specific tests to monitor the presence of opportunistic and pathogenic bacteria (Pseudomonas aeruginosa, Escherichia coli, enterococci, and coliforms). Completely new devices were equipped with a commercially available electrolytic system or with a newly patented one or sanitized by automatic or manual addition of chlorine solutions. In all cases, the contamination was reduced, not completely avoided. In particular, the patented electrolytic system significantly reduced bacterial proliferation in strongly contaminated devices. Our data confirm the difficulties encountered to solve the problem of microbiological quality of softened water and offer encouraging information on new possible solutions.

Sunlight-induced degradation of fluoroquinolones in wastewater effluent: Photoproducts identification and toxicity.

The photodegradation of Ciprofloxacin (CIP), Enrofloxacin (ENR), Danofloxacin (DAN), Marbofloxacin (MAR) and Levofloxacin (LEV), five widely used fluoroquinolones (FQs), was studied in urban WWTP secondary effluent, under solar light. The degradation profiles and the kinetic constants were determined at the micrograms per litre levels (20-50 µg L(-1)). The photo-generated products were identified by high-pressure liquid chromatography coupled to electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS). The toxicity of the photoproducts was assessed by Vibrio fischeri light emission inhibition assay performed on irradiated and not-irradiated FQs solutions, at environmentally significant concentrations. Attention was focused on the evaluation of the photoproducts contribution to the overall biotoxic effect of these emerging pollutants. Data from chronic exposure experiments (24-48 h) were primarily considered. Results confirmed the major usefulness of chronic toxicity data with respect to the acute assay ones and proved the not negligible biotoxicity of the FQs photodegradation products.

Competitive amperometric immunosensor based on covalent linking of a protein conjugate to dendrimer-functionalised nanogold substrate for the determination of 2,4,6-trinitrotoluene.

A new amperometric immunosensor for 2,4,6-trinitrotoluene based on the working principle of competitive enzyme-linked immunosorbent assay was developed and characterised. An electrodeposited nanogold substrate was functionalised by deposition of self-assembled monolayers of 2-aminoethanethiol as linkers for the subsequent immobilisation of polyamidoaminic dendrimers. Our approach makes use of those dendrimers to anchor a trinitrobenzene-ovalbumin conjugate on the electrode surface. The immunosensor was tested and validated for the determination of 2,4,6-trinitrotoluene showing high selectivity with respect to other nitroaromatic compounds, a limit of detection of 4.8 ng/mL and a limit of quantitation of 6 ng/mL. The immunosensor was tested for the quantification of the analyte in spiked soils and in a real sample of post-blast soil, evidencing a good recovery rate (113 %).

Chemiluminescent ELISA for the BTEX determination in water and soil.

An indirect competitive chemiluminescence enzyme-linked immunosorbent assay (CL-ELISA) for the determination of benzene, toluene, ethylbenzene, and ortho-, meta-, para-xylenes (BTEX) in soil and water was developed. The assay was optimized concerning the coating conjugate concentration, anti-BTEX antiserum dilution, incubation time effect on primary and secondary antibody incubation, and temperature effect on the competitive step and tolerance to different organic solvents. The IC(50) and lower limit of the detection (LDD(90)) values were 4.6 and 0.5 microg mL(-1), respectively. While water samples could be analyzed directly, soil has to be extracted and diluted prior to immunochemical measurements. BTEX could be recovered from spiked soil with a yield higher than 60% using 5-min ultrasonication with methanol. Finally, the assay was applied to soil and water samples collected at a contaminated site in Italy, and was compared to GC-MS.

Monitoring of environmental pollutants by bioluminescent bacteria.

This review deals with the applications of bioluminescent bacteria to the environmental analyses, published during the years 2000-2007. The ecotoxicological assessment, by bioassays, of the environmental risks and the luminescent approaches are reported. The review includes a brief introduction to the characteristics and applications of bioassays, a description of the characteristics and applications of natural bioluminescent bacteria (BLB), and a collection of the main applications to organic and inorganic pollutants. The light-emitting genetically modified bacteria applications, as well as the bioluminescent immobilized systems and biosensors are outlined. Considerations about commercially available BLB and BLB catalogues are also reported. Most of the environmental applications, here mentioned, of luminescent organisms are on wastewater, seawater, surface and ground water, tap water, soil and sediments, air. Comparison to other bioindicators and bioassay has been also made. Various tables have been inserted, to make easier to take a rapid glance at all possible references concerning the topic of specific interest.