Background and Purpose-We systematically compared and appraised contemporary guidelines on management of asymptomatic and symptomatic carotid artery stenosis. Methods-We systematically searched for guideline recommendations on carotid endarterectomy (CEA) or carotid angioplasty/stenting (CAS) published in any language between January 1, 2008, and January 28, 2015. Only the latest guideline per writing group was selected. Each guideline was analyzed independently by 2 to 6 authors to determine clinical scenarios covered, recommendations given, and scientific evidence used. Results-Thirty-four eligible guidelines were identified from 23 different regions/countries in 6 languages. Of 28 guidelines with asymptomatic carotid artery stenosis procedural recommendations, 24 (86%) endorsed CEA (recommended it should or may be provided) for ≈50% to 99% average-surgical-risk asymptomatic carotid artery stenosis, 17 (61%) endorsed CAS, 8 (29%) opposed CAS, and 1 (4%) endorsed medical treatment alone. For asymptomatic carotid artery stenosis patients considered high-CEA-risk because of comorbidities, vascular anatomy, or undefined reasons, CAS was endorsed in 13 guidelines (46%). Thirty-one of 33 guidelines (94%) with symptomatic carotid artery stenosis procedural recommendations endorsed CEA for patients with ≈50% to 99% average-CEA-risk symptomatic carotid artery stenosis, 19 (58%) endorsed CAS and 9 (27%) opposed CAS. For high-CEA-risk symptomatic carotid artery stenosis because of comorbidities, vascular anatomy, or undefined reasons, CAS was endorsed in 27 guidelines (82%). Guideline procedural recommendations were based only on results of trials in which patients were randomized 12 to 34 years ago, rarely reflected medical treatment improvements and often understated potential CAS hazards. Qualifying terminology summarizing recommendations or evidence lacked standardization, impeding guideline interpretation, and comparison. This systematic review of contemporary international guidelines was performed to compare and appraise recommendations for the management of patients with ACS and SCS (including accessibility, organization, clarity, and consistency) and the evidence used in making these recommendations. Conclusions-This Methods Guideline SearchesGuidelines with recommendations on the use of CEA or CAS or both patients with ACS or SCS or both were sought systematically using popular search engines, bibliographies, and author professional networks. PubMed and ISI Web of Knowledge were searched independently and synchronously by 2 authors on September 9, 2013 (A.L.A., K.I.P.). PubMed was searched using carotid guideline and then stroke guideline in the title, yielding 91 references after duplicate removal. ISI Web of Knowledge was searched using carotid and guideline and then stroke and guideline in the title, yielding 422 references after removal of duplicates, abstracts, reference materials, letters, corrections, meetings, news, and case reports. Wider searches using the words carotid or stroke and guideline in any ...

Aims: To assess hazards associated with exposure to dust in the London Underground railway and to provide an informed opinion on the risks to workers and the travelling public of exposure to tunnel dust. Methods: Concentrations of dust, as mass (PM 2.5 ) and particle number, were measured at different underground stations and in train cabs; its size and composition were analysed; likely maximal exposures of staff and passengers were estimated; and in vitro toxicological testing of sample dusts in comparison with other dusts was performed. Results: Concentrations on station platforms were 270-480 mg/m 3 PM 2.5 and 14 000-29 000 particles/ cm 3 . Cab concentrations over a shift averaged 130-200 mg/m 3 and 17 000-23 000 particles/cm 3 . The dust comprised by mass approximately 67% iron oxide, 1-2% quartz, and traces of other metals, the residue being volatile matter. The finest particles are drawn underground from the surface while the coarser dust is generated by interaction of brakes, wheels, and rails. Taking account of durations of exposure, drivers and station staff would have maximum exposures of about 200 mg/m 3 over eight hours; the occupational exposure standard for welding fume, as iron oxide, is 5 mg/m 3 over an eight hour shift. Toxicology showed the dust to have cytotoxic and inflammatory potential at high doses, consistent with its composition largely of iron oxide. Discussion: It is unjustifiable to compare PM 2.5 exposure underground with that on the surface, since the adverse effects of iron oxide and combustion generated particles differ. Concentrations of ultrafine particles are lower and of coarser (PM 2.5 ) particles higher underground than on the surface. The concentrations underground are well below allowable workplace concentrations for iron oxide and unlikely to represent a significant cumulative risk to the health of workers or commuters.

Objectives-To measure the concentrations of particles less than 100 nm diameter and of oxides of nitrogen generated by cooking with gas and electricity, to comment on possible hazards to health in poorly ventilated kitchens. Methods-Experiments with gas and electric rings, grills, and ovens were used to compare diVerent cooking procedures. Nitrogen oxides (NO x ) were measured by a chemiluminescent ML9841A NO x analyser. A TSI 3934 scanning mobility particle sizer was used to measure average number concentration and size distribution of aerosols in the size range 10-500 nm.Results-High concentrations of particles are generated by gas combustion, by frying, and by cooking of fatty foods. Electric rings and grills may also generate particles from their surfaces. In experiments where gas burning was the most important source of particles, most particles were in the size range 15-40 nm. When bacon was fried on the gas or electric rings the particles were of larger diameter, in the size range 50-100 nm. The smaller particles generated during experiments grew in size with time because of coagulation. Substantial concentrations of NO X were generated during cooking on gas; four rings for 15 minutes produced 5 minute peaks of about 1000 ppb nitrogen dioxide and about 2000 ppb nitric oxide. Conclusions-Cooking in a poorly ventilated kitchen may give rise to potentially toxic concentrations of numbers of particles. Very high concentrations of oxides of nitrogen may also be generated by gas cooking, and with no extraction and poor ventilation, may reach concentrations at which adverse health eVects may be expected. Although respiratory eVects of exposure to NO x might be anticipated, recent epidemiology suggests that cardiac eVects cannot be excluded, and further investigation of this is desirable. (Occup Environ Med 2001;58:511-516)