BACKGROUND Particulate air pollution has been associated with excess deaths from, and increases in hospital admissions for, cardiovascular disease among older people. A study was undertaken to determine whether this may be a consequence of alterations in the blood, secondary to pulmonary inflammation caused by the action of fine particles on alveolar cells, by repeatedly measuring haematological factors in older people and relating them to measurements of exposure to airborne particles. METHODS One hundred and twelve individuals aged 60+ years in two UK cities provided repeated blood samples over 18 months, 108 providing the maximum of 12 samples. Estimates of individual exposure to particles of less than 10 μm diameter (PM₁₀), derived from a mathematical model based on activity diaries and comparative measurements of PM₁₀ at multiple sites and during a variety of activities, were made for each three day period prior to blood sampling. The relationships between blood values and estimates of both personal exposure and city centre measurements of PM₁₀ were investigated by analysis of covariance, adjusting for city, season, temperature, and repeated individual measurements. RESULTS Estimated personal exposure to PM₁₀ over the previous three days showed negative correlations with haemoglobin concentration, packed cell volume (PCV), and red blood cell count (p<0.001), and with platelets and factor VII levels (p<0.05). The changes in red cell indices persisted after adjustment for plasma albumin in a sample of 60 of the subjects. City centre PM₁₀ measurements over three days also showed negative correlations with haemoglobin and red cell count (p<0.001) and with PCV and fibrinogen (p<0.05), the relationship with haemoglobin persisting after adjustment for albumin. C reactive protein levels showed a positive association with city centre measurements of PM₁₀ (p<0.01). Based on a linear relationship, the estimated change in haemoglobin associated with an alteration in particle concentration of 100 μg/m³ is estimated to have been 0.44 g/dl (95% CI 0.62 to 0.26) for personal PM₁₀ and 0.73 g/dl (95% CI 1.11 to 0.36) for city centre PM₁₀ measurements. CONCLUSIONS This investigation is the first to estimate personal exposures to PM₁₀ and to demonstrate associations between haematological indices and air pollution. The changes in haemoglobin adjusted for albumin suggest that inhalation of some component of PM₁₀may cause sequestration of red cells in the circulation. We propose that an action of such particles either on lung endothelial cells or on erythrocytes themselves may be responsible for changing red cell adhesiveness. Peripheral sequestration of red cells offers an explanation for the observed cardiovascular effects of particulate air pollution.

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 different cooking procedures. Nitrogen oxides (NO_x) were measured by a chemiluminescent ML9841A NO_xanalyser. 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_Xwere 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 effects may be expected. Although respiratory effects of exposure to NO_xmight be anticipated, recent epidemiology suggests that cardiac effects cannot be excluded, and further investigation of this is desirable.

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 μg/m³PM_2.5and 14 000–29 000 particles/cm³. Cab concentrations over a shift averaged 130–200 μg/m³and 17 000–23 000 particles/cm³. 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 μg/m³over eight hours; the occupational exposure standard for welding fume, as iron oxide, is 5 mg/m³over 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_2.5exposure 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.

A sound knowledge base is required to target resources to reduce workplace exposure to carcinogens. This project aimed to provide an objective estimate of the burden of cancer in Britain due to occupation. This volume presents extensive analyses for all carcinogens and occupational circumstances defined as definite or probable human occupational carcinogens by the International Agency for Research on Cancer. This article outlines the structure of the supplement – two methodological papers (statistical approach and exposure assessment), eight papers presenting the cancer-specific results grouped by broad anatomical site, a paper giving industry sector results and one discussing work-related cancer-prevention strategies. A brief summary of the methods and an overview of the updated overall results are given in this introductory paper. A general discussion of the overall strengths and limitations of the study is also presented. Overall, 8010 (5.3%) total cancer deaths in Britain and 13, 598 cancer registrations were attributable to occupation in 2005 and 2004, respectively. The importance of cancer sites such as mesothelioma, sinonasal, lung, nasopharynx, breast, non-melanoma skin cancer, bladder, oesophagus, soft tissue sarcoma and stomach cancers are highlighted, as are carcinogens such as asbestos, mineral oils, solar radiation, silica, diesel engine exhaust, coal tars and pitches, dioxins, environmental tobacco smoke, radon, tetrachloroethylene, arsenic and strong inorganic mists, as well as occupational circumstances such as shift work and occupation as a painter or welder. The methods developed for this project are being adapted by other countries and extended to include social and economic impact evaluation.

Background: Methods: Results: Conclusion:

Background: There is a growing interest in research investigating the association between green space (GS) and mental health and wellbeing (HWB), in order to understand the underlying mechanisms. Accordingly, there is a need to map the literature and create an overview of the research. Methods: A scoping review approach was used to map literature on GS, including context and co-exposures (the GS exposome), and their associations with mental HWB. The review considers mental HWB definitions and measurements and how GS is characterized. Furthermore, the review aims to identify knowledge gaps and make recommendations for future research. Results: We identified a great diversity in study designs, definitions, outcome measures, consideration of the totality of the GS exposome, and reporting of results. Around 70% of the 263 reviewed studies reported a positive association between some aspect of GS and HWB. However, there is a limited amount of research using randomized controlled crossover trails (RCTs) and mixed methods and an abundance of qualitative subjective research. Conclusions: The discords between study designs, definitions, and the reporting of results makes it difficult to aggregate the evidence and identify any potential causal mechanisms. We propose key points to consider when defining and quantifying GS and make recommendations for reporting on research investigating GS and mental HWB. This review highlights a need for large well-designed RCTs that reliably measure the GS exposome in relation to mental HWB.