Occupational Exposure to Polycyclic Aromatic Hydrocarbons and Elevated Cancer Incidence in Firefighters.

Cancer incidence appears to be higher amongst firefighters compared to the general population. Given that many cancers have an environmental component, their occupational exposure to products of carbon combustion such as polycyclic aromatic hydrocarbons (PAHs) is of concern. This is the first UK study identifying firefighters exposure to PAH carcinogens. Wipe samples were collected from skin (jaw, neck, hands), personal protective equipment of firefighters, and work environment (offices, fire stations and engines) in two UK Fire and Rescue Service Stations. Levels of 16 US Environmental Protection Agency (EPA) PAHs were quantified together with more potent carcinogens: 7,12-dimethylbenzo[a]anthracene, and 3-methylcholanthrene (3-MCA) (12 months post-initial testing). Cancer slope factors, used to estimate cancer risk, indicate a markedly elevated risk. PAH carcinogens including benzo[a]pyrene (B[a]P), 3-MCA, and 7,12-dimethylbenz[a]anthracene PAHs were determined on body surfaces (e.g., hands, throat), on PPE including helmets and clothing, and on work surfaces. The main exposure route would appear to be via skin absorption. These results suggest an urgent need to monitor exposures to firefighters in their occupational setting and conduct long-term follow-up regarding their health status.

NP108, an Antimicrobial Polymer with Activity against Methicillin- and Mupirocin-Resistant Staphylococcus aureus.

Staphylococcus aureus is a clinically significant human pathogen that causes infectious diseases ranging from skin and soft tissue infections (SSTI) and health care-associated infections (HAI) to potentially fatal bacteremia and endocarditis. Nasal carriage of S. aureus, especially for persistent carriage, is associated with an increased risk of subsequent infection, particularly nosocomial and surgical site infections (SSI), usually via autoinfection. NP108 is a cationic antimicrobial polymer composed of generally recognized as safe (GRAS) amino acid building blocks. NP108 is broad spectrum and rapidly bactericidal (3-log kill in ≤3 h), killing bacteria by membrane disruption and cell lysis. NP108, contrary to many antibiotics, shows equally effective antimicrobial activity against a variety of S. aureus (MIC100 = 8 to 500 mg/liter) and S. epidermidis (MIC100 = 4 to 8 mg/liter) isolates, whether exponentially growing or in stationary phase. NP108 is antimicrobially active under nutrient-limiting conditions similar to those found in the anterior nares (MIC100 = 8 mg/liter) and kills antibiotic-resilient small colony variants (MIC100 = 32 mg/liter) and S. aureus biofilms (prevention, MIC100 = 1 to 4 mg/liter; eradication, MIC100 ≥ 31.25 mg/liter). NP108 is active against isolates of S. aureus resistant to the current standard-of-care decolonization agent, mupirocin, with no significant increase in the MIC100 NP108 is water soluble and has been formulated into compatible aqueous gel vehicles for human use in which antimicrobial efficacy is retained (2.0% [wt/vol]). NP108 is a potential nonantibiotic antimicrobial alternative to antibiotics for the nasal decolonization of S. aureus, with clear advantages in its mechanism of action over the existing gold standard, mupirocin.

Release of volatile and semi-volatile toxicants during house fires.

Qualitative results are presented from analysis of volatile and semi-volatile organic compounds (VOCs/SVOCs) obtained through sampling of gaseous effluent and condensed particulates during a series of experimental house fires conducted in a real house. Particular emphasis is given to the 16 polycyclic aromatic hydrocarbons (PAHs) listed by the Environmental Protection Agency due to their potentially carcinogenic effects. The initial fuel packages were either cooking oil or a single sofa; these were burned both alone, and in furnished surroundings. Experiments were performed at different ventilation conditions. Qualitative Gas Chromatography-Mass Spectrometry (GC-MS) analysis found VOC/SVOC releases in the developing stages of the fires, and benzo(a)pyrene - the most carcinogenic PAH - was found in at least one sampling interval in the majority of fires. A number of phosphorus fire retardants were detected, in both the gaseous effluent and particulates, from fires where the initial fuel source was a sofa. Their release during the fire is significant as they pose toxicological concerns separate from those presented by the PAHs.

New developments in insecticide resistance in the glasshouse whitefly (Trialeurodes vaporariorum) and the two-spotted spider mite (Tetranychus urticae) in the UK.

A recent survey of insecticide resistance in two of the most problematic pests in UK glasshouses revealed some new developments. At least some individuals in all UK samples of Trialeurodes vaporariorum that were tested resisted the insect growth regulator (IGR) buprofezin. The most strongly resistant strains were unaffected by the field application rate of this compound, and even samples from populations that had never been exposed to buprofezin contained individuals that survived the highest concentration applied (10,000 mg litre-1). The field rate of buprofezin was shown to select for resistance through vapour action alone. The benzophenylurea teflubenzuron, an unrelated IGR, was cross-resisted by buprofezin-resistant individuals. There was no evidence of resistance to imidacloprid, but all T vaporariorum strains tested, regardless of origin, exhibited a high innate tolerance to nicotine, when compared with another whitefly species, Bemisia tabaci. Marked resistance to fenbutatin oxide and tebufenpyrad was found in single glasshouse populations of Tetranychus urticae, but these compounds and abamectin appeared to remain highly effective against all other strains collected.