Documentation exists for many chemicals that cause tastes and odors in water, however, water suppliers do not routinely monitor for these chemicals. Effective management of a taste-and-odor (T&O) problem in drinking water often requires good verbal description of the offending sensory experience. Experience demonstrates that obtaining verbal descriptions is challenging. To improve our understanding of communications, sensory science literature was reviewed to obtain descriptors for twenty-one chemicals acknowledged to cause T&O issues in drinking water. The review focused on pure chemicals above their odor threshold concentrations. Results reveal that descriptors follow four general categories. For select chemicals, strong consensus exists around a single or very few appropriate descriptors. Examples are \"salty\" for sodium and \"chlorinous\" for free chlorine. The next category has moderate agreement for several descriptors, with at least one major descriptor. For example the microbiological metabolite 2-methylisoborneol is most commonly described as \"earthy/musty/moldy\" but also \"camphor, grass, and sweet\". Some chemicals have weak agreement on their descriptors, but overall associate words with similar meaning. An example is the chemical toluene with descriptors of \"solvent-like\" words including \"solvent\", \"gasoline\", \"paint-like\", \"cleaning fluid\", and \"etherish\", but also \"vinegar\" and \"sweet\". The last chemical category possesses diverse descriptors with no consensus. For example, the oxylipin n-heptanal is described as \"oily, fatty, chemical, musty/earthy/moldy, rancid, sweaty, grass, sickening, and stale\". While descriptor diversity for select chemicals may not identify the cause of T&O, understanding that certain chemicals are perceived very differently aids in effective communications and eliminates confusion from expecting consumers or utility personnel to respond with consensus.

Sensory irritation of eyes and upper airways is an important endpoint for setting occupational exposure limits (OELs) and indoor air guidelines. Sensory irritants cause a painful burning, stinging and itching sensation. Controlled chamber studies are the \"golden standard\" for evaluations. Well conducted workplace studies offer another possibility. For generalization, the number of participants and their age, smoking, gender, and prior exposure, experience and mood has to be considered. Exposure assessments have to be reliable and exposure duration sufficiently long to establish time-response relationships. A potential confounding by odour has to be assessed. For workplace exposures, mixed exposure and healthy worker effects have to be evaluated. The \"Alarie test\" is the only validated animal bioassay for prediction of sensory irritation in humans. The mouse bioassay uses the trigeminal reflex-induced decrease in the respiratory rate. The 50% decrease (RD50) has been correlated with OELs set for sensory irritants; predicted OELs for sensory irritants are 0.03xRD50. Evaluation of the bioassay comprises the number of mice and the strain, the reliability of the exposure concentrations and exposure-response relationships, and the similar mode-of-action in mice and humans. These approaches can be used for quality assurance of reported data to set air quality guidelines.

This paper aims at analysing the environmental benefits and impacts associated with the treatment of malodorous emissions from wastewater treatment plants (WWTPs). The life cycle assessment (LCA) methodology was applied to two biological treatments, namely biofilter (BF) and biotrickling filter (BTF), two physical/chemical alternatives, namely activated carbon tower (AC) and chemical scrubber (CS), and a hybrid combination of BTF + AC. The assessment provided consistent guidelines for technology selection, not only based on removal efficiencies, but also on the environmental impact associated with the treatment of emissions. The results showed that biological alternatives entailed the lowest impacts. On the contrary, the use of chemicals led to the highest impacts for CS. Energy use was the main contributor to the impact related to BF and BTF, whereas the production of glass fibre used as infrastructure material played an important role in BTF impact. Production of NaClO entailed the highest burdens among the chemicals used in CS, representing ∼ 90% of the impact associated to chemicals. The frequent replacement of packing material in AC was responsible for the highest environmental impacts, granular activated carbon (GAC) production and its final disposal representing more than 50% of the impact in most categories. Finally, the assessment of BTF + AC showed that the hybrid technology is less recommendable than BF and BTF, but friendlier to the environment than physical/chemical treatments.

There is considerable recent focus and concern about formaldehyde (FA). We have reviewed the literature on FA with focus on chemosensory perception in the airways and lung effects in indoor environments. Concentrations of FA, both personal and stationary, are on average in the order of 0.05 mg/m(3) or less in Europe and North America with the exception of new housing or buildings with extensive wooden surfaces, where the concentration may exceed 0.1 mg/m(3). With the eye the most sensitive organ, subjective irritation is reported at 0.3-0.5 mg/m(3), which is somewhat higher than reported odour thresholds. Objective effects in the eyes and airways occur around 0.6-1 mg/m(3). Dose-response relationships between FA and lung function effects have not been found in controlled human exposure studies below 1 mg/m(3), and epidemiological associations between FA concentrations and exacerbation of asthma in children and adults are encumbered by complex exposures. Neither experimental nor epidemiological studies point to major differences in susceptibility to FA among children, elderly, and asthmatics. People with personal trait of negative affectivity may report more symptoms. An air quality guideline of 0.1 mg/m(3) (0.08 ppm) is considered protective against both acute and chronic sensory irritation in the airways in the general population assuming a log normal distribution of nasal sensory irritation.

House mice (Mus domesticus) communicate using scent-marks, and the chemical and microbial composition of these \'extended phenotypes\' are both influenced by genetics. This study examined how the genes of the major histocompatibility complex (MHC) and background genes influence the volatile compounds (analysed with Gas Chromatography Mass Spectrometry or GC/MS) and microbial communities (analysed using Denaturating Gradient Gel Electrophoresis or DGGE) in scent-marks produced by congenic strains of mice. The use of Consensus Principal Components Analysis is described and shows relationships between the two types of fingerprints (GC/MS and DGGE profiles). Classification methods including Support Vector Machines and Discriminant Partial Least Squares suggest that mice can be classified according to both background strain and MHC-haplotype. As expected, the differences among the mice were much greater between strains that vary at both MHC and background loci than the congenics, which differ only at the MHC. These results indicate that the volatiles in scent-marks provide information about genetic similarity of the mice, and support the idea that the production of these genetically determined volatiles is influenced by commensal microflora. This paper describes the application of consensus methods to relate two blocks of analytical data.

OBJECTIVE: To seek a consensus on recommendations that would help health professionals choose appropriate wound dressings in daily practice, since a systematic review found only limited evidence to support reported indications for modern wound dressings.
METHODS: A steering committee selected a panel of 27 experts with no declared conflicts of interest from lists of nursing staff and physicians (specialists or general practitioners) with long-standing experience of wound care. The lists were put forward by 15 French learned societies.
METHODS: The panelists received a recent systematic review of the literature, a classification of indications established by a working group, and definitions for the dressings.
METHODS: The steering committee designed questionnaires on chronic wounds and on acute wounds including burns for each of the 2 panels. The consensus method was derived from the nominal group technique adapted by RAND/UCLA. Panelists rated the relevance of each possible dressing-indication combination on the basis of the published evidence and their own experience. After the first round of rating, they met to discuss results and propose recommendations before taking part in a second round of rating. The working group peer reviewed the final recommendations.
CONCLUSIONS: A strong consensus was reached for use of the following combinations: for chronic wounds, (1) debridement stage, hydrogels; (2) granulation stage, foam and low-adherence dressings; and (3) epithelialization stage, hydrocolloid and low-adherence dressings; and for the epithelialization stage of acute wounds, low-adherence dressings. For specific situations, the following dressings were favored: for fragile skin, low-adherence dressings; for hemorrhagic wounds, alginates; and for malodorous wounds, activated charcoal.

Partition models based on the octanol-air parition coefficients and associated quantitative structure-activity relationships (QSARs) have been developed to describe the triggering of odor response and nasal irritation by common volatile organic compounds (VOCs). This study made use of the QSARs developed by Hau and Connell (1998, Indoor Air 8, 23-33) and Hau et al. (1999, Toxicol. Sci. 47, 93-98) to evaluate risk-based guidelines on the airborne concentrations of common VOCs in the nonindustrial environment. A new concept referred to as the \"apparent internal threshold concentration\" was developed for evaluating the odor and nasal pungency responses to a typical low-concentration VOC mixture described by Otto et al. (1990, Neurotoxicol. Teratol. 12, 649-652). The assessment indicated that odor can be detected at a total VOC concentration of about 3 mg/m(3), consistent with the findings of Molhave et al. (1991, Atmos. Environ. 25, 1283-1293). Nasal pungency, according to our assessment, should not ocur at a total concentration of 25 mg/m(3), which is apparently in conflict with the findings of Molhave (1986, ASHRAE Trans. 92(1A), 306-316). It can be inferred from this investigation that pure nasal pungency without the influence of odor is unlikely to result from exposure to low-concentration VOC mixtures typically found in the nonindustrial environment.

During a 7 years longitudinal study on a representative group the guideline \"selection and schooling of personal for odour analysis\" was reexamined. It could be shown that the selection in two steps is well suited to recognize anosmia and hyposmia, respectively and that normal osmia is well to be characterized by smell scores of 30-42. A statistical significant training effect could be shown with the qualitative test for training of the odour memory as well as the articulation in describing of smell impressions. The result of the rank order test demonstrate the practicable subdivision of the odour intensity into 5 degrees.