Habitat, morphology and karyotype of the Saharan shrew Crocidura tarfayaensis (Mammalia : Soricidae)

The Saharan shrew Crocidura tarfayaensis Vesmanis and Vesmanis, 1980, has a limited disribution along the Atlantic coast of Sahara, south of Agadir (Morocco) through Western Sahara into Mauritania and is only known from few captures and some owl pellets. Here we report field data from the successful trapping of five specimens of C. tarfayaensis in the Guelmim region. The habitat was characterized by sand dunes along a river, with dense shrubberies of Tamarix sp., the huge grass Erianthus ravennae (Poaceae) and flat bushes of Atriplex glauca var. ifniensis (Chenopodiaceae). Morphological discrimination with C. whitakeri were examined. The chromosomes of C. tarfayaensis revealed a karyotype of 2n = 36, similar to that of the Canary shrew C. canariensis and the Sicilian shrew C. sicula. In conclusion, C. tarfayaensis seems to be a descendant of the presumed continental ancestor of the two island species.

On the cellular site of two-pore channel TPC1 action in the Poaceae.

The slow vacuolar (SV) channel has been characterized in different dicots by patch-clamp recordings. This channel represents the major cation conductance of the largest organelle in most plant cells. Studies with the tpc1-2 mutant of the model dicot plant Arabidopsis thaliana identified the SV channel as the product of the TPC1 gene. By contrast, research on rice and wheat TPC1 suggested that the monocot gene encodes a plasma membrane calcium-permeable channel. To explore the site of action of grass TPC1 channels, we expressed OsTPC1 from rice (Oryza sativa) and TaTPC1 from wheat (Triticum aestivum) in the background of the Arabidopsis tpc1-2 mutant. Cross-species tpc1 complementation and patch-clamping of vacuoles using Arabidopsis and rice tpc1 null mutants documented that both monocot TPC1 genes were capable of rescuing the SV channel deficit. Vacuoles from wild-type rice but not the tpc1 loss-of-function mutant harbor SV channels exhibiting the hallmark properties of dicot TPC1/SV channels. When expressed in human embryonic kidney (HEK293) cells OsTPC1 was targeted to Lysotracker-Red-positive organelles. The finding that the rice TPC1, just like those from the model plant Arabidopsis and even animal cells, is localized and active in lyso-vacuolar membranes associates this cation channel species with endomembrane function.

Perioperative nutrition is still a surgical orphan

Objective: To assess if screening programs and treatment of preoperative malnutrition have been implemented into surgical practice to decrease morbidity. There is strong evidence that postoperative morbidity can be minimized by early identifying and treating patients at nutritional risk before major surgery.The validated nutritional risk score (NRS) is recommended by the European Society of Parenteral and Enteral Nutrition for nutritional screening. It remains unclear whether routine preoperative nutritional assessment and perioperative nutrition is widely implemented.Methods: A survey was conducted in 173 Swiss and Austrian surgical departments. Implementation of nutritional screening, perioperative nutrition, and estimated impact on clinical outcome were assessed. Non-responders were repeatedly contacted by the authors.Results: The overall response rate was 55%, whereby 69% (54/78) of Swiss and 44% (42/95) of Austrian centers responded. Despite 80% and 59% of the responding centers are aware of a reduced complication rate and shortened hospital stay, respectively, only 20% of them implemented routine nutritional screening. Financial (49%) and logistic restrictions (33%) are the predominant reasons against the routine clinical use. Screening is mainly performed either in the outpatient's clinic (52%) or during admission (54%). The NRS is only used by 14%. Instead, various clinical (78%), e.g. BMI and laboratory findings (56%), e.g. albumine, are used. Indication for perioperative nutrition is based on preoperative screening in 49%.While 23% use preoperative nutrition, 68% apply nutritional support pre- and postoperatively. Preoperative nutritional treatment ranged from three days (33%), to five days (31%) and even seven days (20%).Conclusion: Despite malnutrition is well recognized as major risk factor for increased postoperative morbidity, the majority of surgeons are reluctant to implement routine screening and nutritional support. If nutritional assessment is performed, local institutional screening parameters are still preferred. It remains difficult to overcome traditions, and to change surgeon's mind.

A better understanding of ecological conditions for Leontopodium alpinum Cassini in the Swiss Alps

Although Leontopodium alpinum is considered to be threatened in many countries, only limited scientific information about its autecology is available. In this study, we aim to define the most important ecological factors which influence the distribution of L. alpinum in the Swiss Alps. These were assessed at the national scale using species distribution models based on topoclimatic predictors and at the community scale using exhaustive plant inventories. The latter were analysed using hierarchical clustering and principal component analysis, and the results were interpreted using ecological indicator values. L. alpinum was found almost exclusively on base-rich bedrocks (limestone and ultramaphic rocks). The species distribution models showed that the available moisture (dry regions, mostly in the Inner Alps), elevation (mostly above 2000 m.a.s.l.) and slope (mostly >30°) were the most important predictors. The relevés showed that L. alpinum is present in a wide range of plant communities, all subalpine-alpine open grasslands, with a low grass cover. As a light-demanding and short species, L. alpinum requires light at ground level; hence, it can only grow in open, nutrient-poor grasslands. These conditions are met in dry conditions (dry, summer-warm climate, rocky and draining soil, south-facing aspect and/or steep slope), at high elevations, on oligotrophic soils and/or on windy ridges. Base-rich soils appear to also be essential, although it is still unclear if this corresponds to physiological or ecological (lower competition) requirements.

Plant and arbuscular mycorrhizal fungal diversity - are we looking at the relevant levels of diversity and are we using the right techniques?

Fungal symbionts commonly occur in plants influencing host growth, physiology, and ecology (Carlile et al., 2001). However, while whole-plant growth responses to biotrophic fungi are readily demonstrated, it has been much more difficult to identify and detect the physiological mechanisms responsible. Previous work on the clonal grass Glyceria striata has revealed that the systemic fungal endophyte Epichloë glyceriae has a positive effect on clonal growth of its host (Pan & Clay, 2002; 2003). The latest study from these authors, in this issue (pp. 467- 475), now suggests that increased carbon movement in hosts infected by E. glyceriae may function as one mechanism by which endophytic fungi could increase plant growth. Given the widespread distribution of both clonal plants and symbiotic fungi, this research will have implications for our understanding of the ecology and evolution of fungus-plant associations in natural communities.

Exotic taxa less related to native species are more invasive.

Some species introduced into new geographical areas from their native ranges wreak ecological and economic havoc in their new environment. Although many studies have searched for either species or habitat characteristics that predict invasiveness of exotic species, the match between characteristics of the invader and those of members of the existing native community may be essential to understanding invasiveness. Here, we find that one metric, the phylogenetic relatedness of an invader to the native community, provides a predictive tool for invasiveness. Using a phylogenetic supertree of all grass species in California, we show that highly invasive grass species are, on average, significantly less related to native grasses than are introduced but noninvasive grasses. The match between the invader and the existing native community may explain why exotic pest species are not uniformly noxious in all novel habitats. Relatedness of invaders to the native biota may be one useful criterion for prioritizing management efforts of exotic species.

Preoperative immunonutrition in patients at nutritional risk: results of a double-blinded randomized clinical trial.

Background/Objectives:To evaluate the impact of preoperative immunonutrition (IN) on postoperative morbidity in patients at risk of malnutrition undergoing major gastrointestinal (GI) surgery.Subjects/Methods:The combination of malnutrition and major GI surgery entails high morbidity. The Nutritional Risk Score (NRS) reliably identifies patients who need preoperative nutrition; the optimal nutritional formula for these patients still needs to be defined. In all, 152 patients with a NRS3 and undergoing elective major GI surgery were randomized between IN or isocaloric-isonitrogenous nutrition (ICN) given for 5 days preoperatively. Patients and caregivers were blinded for the allocated intervention. Thirty days complication rate was the primary endpoint. Infections, length of hospital stay and compliance were considered as secondary outcomes.Results:Overall, 145 patients were available for analysis; the 73 patients in the IN group matched well with the 72 ICN patients with regards to patient's and surgical characteristics. In all, 39 IN and 33 ICN patients experienced a total of 48 and 50 postoperative complications, respectively (P=0.723). Both groups did not differ significantly concerning infectious (13 vs 9) complications. Independent risk factors for overall complications were malignant disease (odds ratio (OR)=4.304; confidence interval (CI) 1.317-14.002) and operative time (OR=1.004; CI 1.000-1.008).Conclusion:In patients at nutritional risk, complications, infections and hospital stay after major GI surgery were comparable regardless of preoperative supplementation with IN or ICN.

Eotaxin-1 (CCL11) up-regulation in tears during seasonal allergic conjunctivitis.

PURPOSE: To compare in-season eotaxin-1 levels in tears of patients suffering from seasonal allergic conjunctivitis (SAC) with (1) tears of normal subjects and (2) tears of SAC patients out of season. METHODS: Tears of 11 SAC patients and six control volunteers were collected during the pollen season. Tears of five SAC patients showing a strong sensitivity to grass pollen (skin-prick tests and specific serum IgE) were collected both in season and out of season. ELISA measured eotaxin-1 level. RESULTS: Eotaxin-1 concentration in tears of SAC patients [2,100+/-503 (SEM) pg/ml] and normal subjects (1,193+/-176 pg/ml) were significantly different (P=0.0049). Regarding allergic patients, the clinical score (sum of five allergic criteria) was significantly different in season and out of season (P=0.0043) as was also the case with eotaxin-1 concentration (P=0.024). CONCLUSIONS: The eotaxin-1 concentration in tears of patients showing hay fever could confirm a diagnosis of seasonal ocular allergy.

Immunonutrition in gastrointestinal surgery.

Background: Patients undergoing major gastrointestinal surgery are at increased risk of developing complications. The use of immunonutrition (IN) in such patients is not widespread because the available data are heterogeneous, and some show contradictory results with regard to complications, mortality and length of hospital stay. Methods: Randomized controlled trials (RCTs) published between January 1985 and September 2009 that assessed the clinical impact of perioperative enteral IN in major gastrointestinal elective surgery were included in a meta-analysis. Results: Twenty-one RCTs enrolling a total of 2730 patients were included in the meta-analysis. Twelve were considered as high-quality studies. The included studies showed significant heterogeneity with respect to patients, control groups, timing and duration of IN, which limited group analysis. IN significantly reduced overall complications when used before surgery (odds ratio (OR) 0.48, 95 per cent confidence interval (c.i.) 0.34 to 0.69), both before and after operation (OR 0.39, 0.28 to 0.54) or after surgery (OR 0.46, 0.25 to 0.84). For these three timings of IN administration, ORs of postoperative infection were 0.36 (0.24 to 0.56), 0.41 (0.28 to 0.58) and 0.53 (0.40 to 0.71) respectively. Use of IN led to a shorter hospital stay: mean difference -2.12 (95 per cent c.i. -2.97 to -1.26) days. Beneficial effects of IN were confirmed when low-quality trials were excluded. Perioperative IN had no influence on mortality (OR 0.90, 0.46 to 1.76). Conclusion: Perioperative enteral IN decreases morbidity and hospital stay but not mortality after major gastrointestinal surgery; its routine use can be recommended.

The serine-rich N-terminal region of Arabidopsis phytochrome A is required for protein stability.

Deletion or substitution of the serine-rich N-terminal stretch of grass phytochrome A (phyA) has repeatedly been shown to yield a hyperactive photoreceptor when expressed under the control of a constitutive promoter in transgenic tobacco or Arabidopsis seedlings retaining their native phyA. These observations have lead to the proposal that the serine-rich region is involved in negative regulation of phyA signaling. To re-evaluate this conclusion in a more physiological context we produced transgenic Arabidopsis seedlings of the phyA-null background expressing Arabidopsis PHYA deleted in the sequence corresponding to amino acids 6-12, under the control of the native PHYA promoter. Compared to the transgenic seedlings expressing wild-type phyA, the seedlings bearing the mutated phyA showed normal responses to pulses of far-red (FR) light and impaired responses to continuous FR light. In yeast two-hybrid experiments, deleted phyA interacted normally with FHY1 and FHL, which are required for phyA accumulation in the nucleus. Immunoblot analysis showed reduced stability of deleted phyA under continuous red or FR light. The reduced physiological activity can therefore be accounted for by the enhanced destruction of the mutated phyA. These findings do not support the involvement of the serine-rich region in negative regulation but they are consistent with a recent report suggesting that phyA turnover is regulated by phosphorylation.

Phylogenetic analyses of C4 photosynthesis evolution in grasses: genetics of convergence and convergence of genes

Summary : During the evolutionary diversification of organisms, similar ecological constraints led to the recurrent appearances of the same traits (phenotypes) in distant lineages, a phenomenon called convergence. In most cases, the genetic origins of the convergent traits remain unknown, but recent studies traced the convergent phenotypes to recurrent alterations of the same gene or, in a few cases, to identical genetic changes. However, these cases remain anecdotal and there is a need for a study system that evolved several times independently and whose genetic determinism is well resolved and straightforward, such as C4 photosynthesis. This adaptation to warm environments, possibly driven by past atmospheric CO2 decreases, consists in a CO2-concentrating pump, created by numerous morphological and biochemical novelties. All genes encoding C4 enzymes already existed in C3 ancestors, and are supposed to have been recruited through gene duplication followed by neo-functionalization, to acquire the cell specific expression pattern and altered kinetic properties that characterize Ca-specific enzymes. These predictions have so far been tested only in species-poor and ecologically marginal C4 dicots. The monocots, and especially the grass family (Poaceae), the most important C4 family in terms of species number, ecological dominance and economical importance, have been largely under-considered as suitable study systems. This thesis aimed at understanding the evolution of the C4 trait in grasses at a molecular level and to use the genetics of C4 photosynthesis to infer the evolutionary history of the C4 phenotype and its driving selective pressures. A molecular phylogeny of grasses and affiliated monocots identified 17 to 18 independent acquisitions of the C4 pathway in the grass family. A relaxed molecular clock was used to date these events and the first C4 evolution was estimated in the Chloridoideae subfamily, between 32-25 million years ago, at a period when atmospheric CO2 abruptly declined. Likelihood models showed that after the COZ decline the probability of evolving the C4 pathway strongly increased, confirming low CO2 as a likely driver of C4 photosynthesis evolution. In order to depict the genetic changes linked to the numerous C4 origins, genes encoding phopshoenolpyruvate carboxylase (PEPC), the key-enzyme responsible for the initial fixation of atmospheric CO2 in the C4 pathway, were isolated from a large sample of C3 and C4 grasses. Phylogenetic analyses were used to reconstruct the evolutionary history of the PEPC multigene family and showed that the evolution of C4-specific PEPC had been driven by positive selection on 21 codons simultaneously in up to eight C4 lineages. These selective pressures led to numerous convergent genetic changes in many different C4 clades, highlighting the repeatability of some evolutionary processes, even at the molecular level. PEPC C4-adaptive changes were traced and used to show multiple appearances of the C, pathway in clades where species tree inferences were unable to differentiate multiple C4 appearances and a single appearance followed by C4 to C3 reversion. Further investigations of genes involved in some of the C4 subtypes only (genes encoding decarboxylating enzymes NADP-malic enzyme and phosphoenolpyruvate carboxykinase) showed that these C4-enzymes also evolved through strong positive selection and underwent parallel genetic changes during the different Ca origins. The adaptive changes on these subtype-specific C4 genes were used to retrace the history of the C4-subtypes phenotypes, which revealed that the evolution of C4-PEPC and C4-decarboxylating enzymes was in several cases disconnected, emphasizing the multiplicity of the C4 trait and the gradual acquisition of the features that create the CO2-pump. Finally, phylogenetic analyses of a gene encoding the Rubisco (the enzyme responsible for the fixation of CO2 into organic compounds in all photosynthetic organisms) showed that C4 evolution switched the selective pressures on this gene. Five codons were recurrently mutated to adapt the enzyme kinetics to the high CO2 concentrations of C4 photosynthetic cells. This knowledge could be used to introgress C4-like Rubisco in C3 crops, which could lead to an increased yield under predicted future high CO2 atmosphere. Globally, the phylogenetic framework adopted during this thesis demonstrated the widespread occurrence of genetic convergence on C4-related enzymes. The genetic traces of C4 photosynthesis evolution allowed reconstructing events that happened during the last 30 million years and proved the usefulness of studying genes directly responsible for phenotype variations when inferring evolutionary history of a given trait. Résumé Durant la diversification évolutive des organismes, des pressions écologiques similaires ont amené à l'apparition récurrente de certains traits (phénotypes) dans des lignées distantes, un phénomène appelé évolution convergente. Dans la plupart des cas, l'origine génétique des traits convergents reste inconnue mais des études récentes ont montré qu'ils étaient dus dans certains cas à des changements répétés du même gène ou, dans de rares cas, à des changements génétiques identiques. Malgré tout, ces cas restent anecdotiques et il y a un réel besoin d'un système d'étude qui ait évolué indépendamment de nombreuses fois et dont le déterminisme génétique soit clairement identifié. La photosynthèse dite en Ça répond à ces critères. Cette adaptation aux environnements chauds, dont l'évolution a pu être encouragé par des baisses passées de la concentration atmosphérique en CO2, est constituée de nombreuses nouveautés morphologiques et biochimiques qui créent une pompe à CO2. La totalité des gènes codant les enzymes Ç4 étaient déjà présents dans les ancêtres C3. Leur recrutement pour la photosynthèse Ç4 est supposé s'être fait par le biais de duplications géniques suivies par une néo-fonctionnalisation pour leur conférer l'expression cellule-spécifique et les propriétés cinétiques qui caractérisent les enzymes C4. Ces prédictions n'ont jusqu'à présent été testées que dans des familles C4 contenant peu d'espèces et ayant un rôle écologique marginal. Les graminées (Poaceae), qui sont la famille C4 la plus importante, tant en termes de nombre d'espèces que de dominance écologique et d'importance économique, ont toujours été considérés comme un système d'étude peu adapté et ont fait le sujet de peu d'investigations évolutives. Le but de cette thèse était de comprendre l'évolution de la photosynthèse en C4 chez les graminées au niveau génétique et d'utiliser les gènes pour inférer l'évolution du phénotype C4 ainsi que les pressions de sélection responsables de son évolution. Une phylogénie moléculaire de la famille des graminées et des monocotylédones apparentés a identifié 17 à 18 acquisitions indépendantes de la photosynthèse chez les graminées. Grâce à une méthode d'horloge moléculaire relâchée, ces évènements ont été datés et la première apparition C4 a été estimée dans la sous-famille des Chloridoideae, il y a 32 à 25 millions d'années, à une période où les concentrations atmosphériques de CO2 ont décliné abruptement. Des modèles de maximum de vraisemblance ont montré qu'à la suite du déclin de CO2, la probabilité d'évoluer la photosynthèse C4 a fortement augmenté, confirmant ainsi qu'une faible concentration de CO2 est une cause potentielle de l'évolution de la photosynthèse C4. Afin d'identifier les mécanismes génétiques responsables des évolutions répétées de la photosynthèse C4, un segment des gènes codant pour la phosphoénolpyruvate carboxylase (PEPC), l'enzyme responsable de la fixation initiale du CO2 atmosphérique chez les plantes C4, ont été séquencés dans une centaine de graminées C3 et C4. Des analyses phylogénétiques ont permis de reconstituer l'histoire évolutive de la famille multigénique des PEPC et ont montré que l'évolution de PEPC spécifiques à la photosynthèse Ça a été causée par de la sélection positive agissant sur 21 codons, et ce simultanément dans huit lignées C4 différentes. Cette sélection positive a conduit à un grand nombre de changements génétiques convergents dans de nombreux clades différents, ce qui illustre la répétabilité de certains phénomènes évolutifs, et ce même au niveau génétique. Les changements sur la PEPC liés au C4 ont été utilisés pour confirmer des évolutions indépendantes du phénotype C4 dans des clades où l'arbre des espèces était incapable de différencier des apparitions indépendantes d'une seule apparition suivie par une réversion de C4 en C3. En considérant des gènes codant des protéines impliquées uniquement dans certains sous-types C4 (deux décarboxylases, l'enzyme malique à NADP et la phosphoénolpyruvate carboxykinase), des études ultérieures ont montré que ces enzymes C4 avaient elles-aussi évolué sous forte sélection positive et subi des changements génétiques parallèles lors des différentes origines de la photosynthèse C4. Les changements adaptatifs sur ces gènes liés seulement à certains sous-types C4 ont été utilisés pour retracer l'histoire des phénotypes de sous-types C4, ce qui a révélé que les caractères formant le trait C4 ont, dans certains cas, évolué de manière déconnectée. Ceci souligne la multiplicité du trait C4 et l'acquisition graduelle de composants participant à la pompe à CO2 qu'est la photosynthèse C4. Finalement, des analyses phylogénétiques des gènes codant pour la Rubisco (l'enzyme responsable de la fixation du CO2 en carbones organiques dans tous les organismes photosynthétiques) ont montré que l'évolution de la photosynthèse Ça a changé les pressions de sélection sur ce gène. Cinq codons ont été mutés de façon répétée afin d'adapter les propriétés cinétiques de la Rubisco aux fortes concentrations de CO2 présentes dans les cellules photosynthétiques des plantes C4. Globalement, l'approche phylogénétique adoptée durant cette thèse de doctorat a permis de démontré des phénomène fréquents de convergence génétique sur les enzymes liées à la photosynthèse C4. Les traces génétiques de l'évolution de la photosynthèse C4 ont permis de reconstituer des évènements qui se sont produits durant les derniers 30 millions d'années et ont prouvé l'utilité d'étudier des gènes directement responsables des variations phénotypiques pour inférer l'histoire évolutive d'un trait donné.

Uranium-enrichment in soils and plants in the vicinity of a pitchblende vein at La Creusaz-Les Marecottes (W of Martigny, Valais, Switzerland)

In the NE part of the Aiguilles Rouges Massif near Martigny, at the eastern contact of the Variscan Vallorcine granite to adjacent gneisses, a series of pitchblende (UO2)-veins occur. This paper determines the level of enrichment and mobility of uranium in soils situated in the vicinity of such a UO2-vein 7 km west of Martigny. Within an area of 50 x 100 m, situated on a relatively steep slope and characterized by a strong gramma-ray anomaly, six soil profiles including their plant cover and a reference soil profile outside the influence of the UO2-vein have been examined. The soil shows pH-values between 4 and 5 and is colluvial. The applied analytical methods for the metal contents include extraction methods, common for soil studies, and bulk analysis performed with X-ray fluorescence and ICP-MS. Uranium contents found in the uppermost 20 cm of the soil profiles vary from 2,500 ppm close to the vein to 15 ppm at the lowermost point of the study area. The reference soil has around 3 ppm uranium. At greater depth (20 to 40 cm) the U-content decreases to about half of the surface values, indicating a vertical transport of uranium within the soil profile. No systematic dependance of uranium-contents to grain size (amount of clay) nor to the amount of organic matter has been found. However, the good correlation between uranium and free iron oxide concentration suggests adsorption of uranium on iron oxy-hydroxides. The ashes of grass and mosses contain up to 90 ppm U, the blueberry and redwood only up to 3 ppm. Our observations suggest that at the surface the uranium is transported by downhill creep (solifluxion) of uranium-rich rock fragments. Liberated by oxidation of the uppermost fragments in a given soil column, the uranium migrates vertically until the conditions are favourable to adsorption onto Fe-oxy-hydroxides. However, as high U-contents of local surface water show, this adsorption does not lead to a significant retention of the uranium.

Exposure of highway maintenance workers to fine particulate matter and noise

In this study, we assessed the mixed exposure of highway maintenance workers to airborne particles, noise, and gaseous co-pollutants. The aim was to provide a better understanding of the workers' exposure to facilitate the evaluation of short-term effects on cardiovascular health endpoints. To quantify the workers' exposure, we monitored 18 subjects during 50 non-consecutive work shifts. Exposure assessment was based on personal and work site measurements and included fine particulate matter (PM2.5), particle number concentration (PNC), noise (Leq), and the gaseous co-pollutants: carbon monoxide, nitrogen dioxide, and ozone. Mean work shift PM2.5 concentrations (gravimetric measurements) ranged from 20.3 to 321 μg m(-3) (mean 62 μg m(-3)) and PNC were between 1.6×10(4) and 4.1×10(5) particles cm(-3) (8.9×10(4) particles cm(-3)). Noise levels were generally high with Leq over work shifts from 73.3 to 96.0 dB(A); the averaged Leq over all work shifts was 87.2 dB(A). The highest exposure to fine and ultrafine particles was measured during grass mowing and lumbering when motorized brush cutters and chain saws were used. Highest noise levels, caused by pneumatic hammers, were measured during paving and guardrail repair. We found moderate Spearman correlations between PNC and PM2.5 (r = 0.56); PNC, PM2.5, and CO (r = 0.60 and r = 0.50) as well as PNC and noise (r = 0.50). Variability and correlation of parameters were influenced by work activities that included equipment causing combined air pollutant and noise emissions (e.g. brush cutters and chain saws). We conclude that highway maintenance workers are frequently exposed to elevated airborne particle and noise levels compared with the average population. This elevated exposure is a consequence of the permanent proximity to highway traffic with additional peak exposures caused by emissions of the work-related equipment.