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Atmospheric samples have been collected between 14 March and 12 September 2012 on a 2-week basis (15 days of sampling and exchange of traps each 7 days) in Strasbourg (east of France) for the analysis of 43 pesticides. Samples (particle and gas phases) were separately extracted using Accelerated Solvent Extraction (ASE) and pre-concentrated by Solid Phase Micro-Extraction (SPME) before analysis by gas chromatography coupled to tandem mass spectrometry (GC-MS/MS). Four SPME consecutive injections at distinct temperatures were made in order to increase the sensitivity of detection for the all monitored pesticides. Currently used detected pesticides can be grouped in four classes; those used in maize crops (acetochlor, benoxacor, dicamba, s-metolachlor, pendimethalin, and bromoxynil), in cereal crops (benoxacor, chlorothalonil, fenpropimorph, and propiconazole), in vineyards (tebuconazole), and as herbicides for orchards, meadows of green spaces (2,4-MCPA, trichlopyr). This is in accordance with the diversity of crops found in the Alsace region and trends observed are in accordance with the period of application of these pesticides. Variations observed permit also to demonstrate that the long time sampling duration used in this study is efficient to visualize temporal variations of airborne pesticides concentrations. Then, long time high-volume sampling could be a simple method permitting atmospheric survey of atmospheric contamination without any long analysis time and consequently low cost.

Larval therapy is a biological 'dressing' for chronic ulcers which is used for debridement, to initiate healing and to reduce bacteria and unpleasant odour. One condition for being able to employ larval therapy is access to disinfected larvae of good quality. We therefore started rearing Lucilia sericata larvae in 1998. Rearing necrophagous larvae in a hospital setting makes it essential to control odour. The improvement of the method includes the use of a controlled, humid, warm environment with artificial light and inexpensive disposable material, as well as the use of ready-made, constantly available and aseptically produced nutrition for feeding larvae and flies. With equipment such as a refrigerator and freezer, larval food is kept fresh and odour-free and chloramine solution is used to disinfect the eggs and thus the larvae. Adhering to a proposed weekly working schedule makes the rearing procedure effective and reliable.

Sir, For centuries, larval therapy has been recognized as an aid in wound healing. During the 1930s and 1940s, before the antibiotic era, larval therapy was commonly used by surgeons in the USA and Europe when treating various soft-tissue and bone infections. The most commonly used larval species is Lucilia sericata (LS). From a clinical point of view, the two major effects of larval therapy have been ascribed to their antibacterial and debriding mechanisms (1 – 4). In regard to the latter function it has been speculated that the larvae, when introduced into the wound, secrete proteolytic enzymes that enable them to degrade and ingest necrotic tissue. Here, we address this question and demonstrate that these larvae secrete a group of serine proteases when cultured in vitro. Furthermore, these serine proteases were detected in the wound fluid of a patient with a chronic leg ulcer treated with larvae. The data suggest that serine proteases of LS are released during treatment.