Thunderstorm asthma is a term used to describe an observed increase in acute bronchospasm cases following the occurrence of thunderstorms in the local vicinity. The roles of accompanying ...meteorological features and aeroallergens, such as pollen grains and fungal spores, have been studied in an effort to explain why thunderstorm asthma does not accompany all thunderstorms. Despite published evidence being limited and highly variable in quality due to thunderstorm asthma being a rare event, this article reviews this evidence in relation to the role of aeroallergens, meteorological features and the impact of thunderstorm asthma on health services. This review has found that several thunderstorm asthma events have had significant impacts on individuals' health and health services with a range of different aeroallergens identified. This review also makes recommendations for future public health advice relating to thunderstorm asthma on the basis of this identified evidence.
Background:Air pollution from biomass fuels in Africa is a significant cause of mortality and morbidity both in adults and children. The work describes the nature and quantity of smoke exposure from ...biomass fuel in Malawian homes.Methods:Markers of indoor air quality were measured in 62 homes (31 rural and 31 urban) over a typical 24 h period. Four different devices were used (one gravimetric device, two photometric devices and a carbon monoxide (HOBO) monitor. Gravimetric samples were analysed for transition metal content. Data on cooking and lighting fuel type together with information on indicators of socioeconomic status were collected by questionnaire.Results:Respirable dust levels in both the urban and rural environment were high with the mean (SD) 24 h average levels being 226 μg/m3 (206 μg/m3). Data from real-time instruments indicated respirable dust concentrations were >250 μg/m3 for >1 h per day in 52% of rural homes and 17% of urban homes. Average carbon monoxide levels were significantly higher in urban compared with rural homes (6.14 ppm vs 1.87 ppm; p<0.001). The transition metal content of the smoke was low, with no significant difference found between urban and rural homes.Conclusions:Indoor air pollution levels in Malawian homes are high. Further investigation is justified because the levels that we have demonstrated are hazardous and are likely to be damaging to health. Interventions should be sought to reduce exposure to concentrations less harmful to health.
Objective: To measure the inflammatory and autonomic responses of healthy humans and patients with coronary artery disease to controlled concentrations of two specific components of vehicle derived ...air pollution, carbon particles and sulphur dioxide (SO2). Methods: Placebo controlled, double blind, random order human challenge study examining the effects of carbon particles (50 μg/m3) and SO2 (200 parts per billion (ppb)) on heart rate variability (HRV) and circulating markers of inflammation and coagulation in healthy volunteers and patients with stable angina. Results: In healthy volunteers, markers of cardiac vagal control did not fall in response to particle exposure but, compared with the response to air, increased transiently immediately after exposure (root mean square of successive RR interval differences (RMSSD) 15 (5) ms with carbon particles and 4 (3) ms) with air, p < 0.05). SO2 exposure resulted in no immediate change but a significant reduction in HRV markers of cardiac vagal control at four hours (RMSSD −2 (3.6) ms with air, −7 (2.7) ms with SO2, p < 0.05). No such changes were seen in patients with stable angina. Neither pollutant caused any change in markers of inflammation or coagulation at zero, four, or 24 hours. Conclusion: In healthy volunteers, short term exposure to pure carbon particles does not cause adverse effects on HRV or a systemic inflammatory response. The adverse effects of vehicle derived particulates are likely to be caused by more reactive species found on the particle surface. SO2 exposure does, however, reduce cardiac vagal control, a response that would be expected to increase susceptibility to ventricular arrhythmia.
This introduction to the special issue provides a context for the contributing articles. for readers who are not familiar with cognitive load theory (CLT), it provides a very brief description of ...assumptions regarding memory systems and learning processes, different types of cognitive load (intrinsic, extraneous, and germane), and design implications. Whereas traditional CLT research focused on instructional methods to decrease extraneous cognitive load that is not directly relevant for learning, contributions to this special issue represent wider perspectives that reflect new developments in CLT. These articles have been organized into three categories: (a) methods to decrease intrinsic cognitive load, and deal with high-element interactivity materials, (b) methods to increase germane cognitive load that is directly relevant for learning, and (c) methods to deal with differences in learner's individual levels of expertise and expertise development. To conclude, design implications for (adaptive) e-learning are discussed.
Abstract
More than half the world's population still rely on burning biomass fuels to heat and light their homes and cook food. Household air pollution, a common component of which is inhalable ...particulate matter (PM), emitted from biomass burning is associated with increased vulnerability to respiratory infection and an enhanced risk of developing chronic obstructive pulmonary disease. In the light of an emerging hypothesis linking chronic PM exposure during childhood and increased vulnerability to respiratory diseases in adulthood, in a chain of events involving oxidative stress, reduced immunity and subsequent infection, the aim of this study was to characterise the oxidative potential (OP) of PM collected during the burning of wood and mixed biomass, whilst cooking food in the Kathmandu Valley, Nepal. Our assessments were based on the capacity of the particles to deplete the physiologically relevant antioxidants from a validated, synthetic respiratory tract lining fluid (RTLF). Incubation of mixed biomass and wood smoke particles suspensions with the synthetic RTLF for 4 h resulted in a mean loss of ascorbate of 64.76 ± 16.83% and 83.37 ± 14.12% at 50 μg/ml, respectively. Reduced glutathione was depleted by 49.29 ± 15.22% in mixed biomass and 65.33 ± 13.01% in wood smoke particles under the same conditions. Co-incubation with the transition metal chelator diethylenetriaminepentaacetate did not inhibit the rate of ascorbate oxidation, indicating a negligible contribution by redox-active metals in these samples. The capacity of biomass smoke particles to elicit oxidative stress certainly has the potential to contribute towards negative health impacts associated with traditional domestic fuels in the developing world.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Chronic obstructive pulmonary disease (COPD) is a common, progressive respiratory disease that causes great morbidity and mortality despite treatment. There is evidence for airway inflammation in ...COPD. Cilomilast is an orally active, potent, selective phosphodiesterase type 4 inhibitor, which in vitro can affect cells thought to be of clinical importance in COPD. Our aim was to assess the safety, efficacy, and dose response of cilomilast in the treatment of patients with this disease.
We did a 6-week, randomised, dose-ranging study in 424 patients with COPD (forced expiratory volume in 1 s FEV1 46·8% of predicted, FEV1/forced vital capacity FVC 54·6%, and postsalbutamol reversibility 5·4%). We randomly assigned individuals at 60 European centres to receive cilomilast 5 (n=109), 10 (n=102), or 15 (n=107) mg twice daily, or placebo (n=106). The main outcome measure was trough FEV1 before and after use of a bronchodilator. Analyses were by intention to treat.
Cilomilast 15 mg twice daily significantly improved FEV1 compared with placebo (mean 130 mL vs −30 mL 95% Cl 90–240 at week 6, p<0·0001). FVC and peak expiratory flow were also improved (p=0·001 and p<0·0001, respectively). Quality of life measures did not differ significantly between the groups. There were no significant differences in serious adverse events between the groups.
Cilomilast 15 mg twice daily might be an effective maintenance treatment for COPD. Further clinical studies are underway.
Objective:To examine changes in the health of bar workers after smoke-free legislation was introduced.Design:Longitudinal study following bar workers from before legislation introduction, at 2 months ...after introduction and at 1 year to control for seasonal differences.Setting:Bars across a range of socio-economic settings in Scotland.Participants:371 bar workers recruited from 72 bars.Intervention:Introduction of smoke-free legislation prohibiting smoking in enclosed public places, including bars.Main outcomes measures:Change in prevalence of self-reported respiratory and sensory symptoms.Results:Of the 191 (51%) workers seen at 1-year follow-up, the percentage reporting any respiratory symptom fell from 69% to 57% (p = 0.02) and for sensory symptoms from 75% to 64% (p = 0.02) following reductions in exposure, effects being greater at 2 months, probably partly due to seasonal effects. Excluding respondents who reported having a cold at either baseline or 1 year, the reduction in respiratory symptoms was similar although greater for “any” sensory symptom (69% falling to 54%, p = 0.011). For non-smokers (n = 57) the reductions in reported symptoms were significant for phlegm production (32% to 14%, p = 0.011) and red/irritated eyes (44% to 18%, p = 0.001). Wheeze (48% to 31%, p = 0.006) and breathlessness (42% to 29%, p = 0.038) improved significantly in smokers. There was no relationship between change in salivary cotinine levels and change in symptoms.Conclusions:Bar workers in Scotland reported significantly fewer respiratory and sensory symptoms 1 year after their working environment became smoke free. As these improvements, controlled for seasonal variations, were seen in both non-smokers and smokers, smoke-free working environments may have potentially important benefits even for smokers.
There are limited data describing pollutant levels inside homes that burn solid fuel within developed country settings with most studies describing test conditions or the effect of interventions. ...This study recruited homes in Ireland and Scotland where open combustion processes take place. Open combustion was classified as coal, peat, or wood fuel burning, use of a gas cooker or stove, or where there is at least one resident smoker. Twenty‐four‐hour data on airborne concentrations of particulate matter <2.5 μm in size (PM2.5), carbon monoxide (CO), endotoxin in inhalable dust and carbon dioxide (CO2), together with 2–3 week averaged concentrations of nitrogen dioxide (NO2) were collected in 100 houses during the winter and spring of 2009–2010. The geometric mean of the 24‐h time‐weighted‐average (TWA) PM2.5 concentration was highest in homes with resident smokers (99 μg/m3– much higher than the WHO 24‐h guidance value of 25 μg/m3). Lower geometric mean 24‐h TWA levels were found in homes that burned coal (7 μg/m3) or wood (6 μg/m3) and in homes with gas cookers (7 μg/m3). In peat‐burning homes, the average 24‐h PM2.5 level recorded was 11 μg/m3. Airborne endotoxin, CO, CO2, and NO2 concentrations were generally within indoor air quality guidance levels.
Practical Implications
Little is known about indoor air quality (IAQ) in homes that burn solid or fossil‐derived fuels in economically developed countries. Recent legislative changes have moved to improve IAQ at work and in enclosed public places, but there remains a real need to begin the process of quantifying the health burden that arises from indoor air pollution within domestic environments. This study demonstrates that homes in Scotland and Ireland that burn solid fuels or gas for heating and cooking have concentrations of air pollutants generally within guideline levels. Homes where combustion of cigarettes takes place have much poorer air quality.
A randomised trial of 178 patients in Aberdeen, UK with a previous hospital admission for chronic obstructive pulmonary disease (COPD) was carried out in order to determine whether improving home ...energy efficiency improves health-related quality of life in COPD patients. 118 patients were randomised and 60 agreed to monitoring only. Energy efficiency upgrading was carried out in 42% of homes randomised to intervention. Independent energy efficiency action was taken by 15% of control participants and 18% in the monitoring group. The main outcome measures were respiratory and general health status, home energy efficiency and hospital admissions. Intention-to-treat analysis found no difference in outcomes between the two groups. In 45 patients, who had energy efficiency action independent of original randomisation, there were significant improvements in respiratory symptom scores (adjusted mean 9.0, 95% CI 2.5-15.5), decreases in estimated annual fuel costs (- pound65.3, 95% CI - pound31.9- - pound98.7) and improved home energy efficiency rating (1.1, 95% CI 0-1.4). COPD patients are unlikely to take up home energy efficiency upgrading, if offered. Secondary "pragmatic" analysis suggests that those who do take action may achieve clinically significant improvement in respiratory health, which is not associated with an increase in indoor warmth.
Ten principles for clean air Brunekreef, B; Annesi-Maesano, I; Ayres, J G ...
The European respiratory journal,
03/2012, Letnik:
39, Številka:
3
Journal Article
PDF
