Cardiovascular health and particulate vehicular emissions: a critical evaluation of the evidence

A major public health goal is to determine linkages between specific pollution sources and adverse health outcomes. This paper provides an integrative evaluation of the database examining effects of vehicular emissions, such as black carbon (BC), carbonaceous gasses, and ultrafine PM, on cardiovascular (CV) morbidity and mortality. Less than a decade ago, few epidemiological studies had examined effects of traffic emissions specifically on these health endpoints. In 2002, the first of many studies emerged finding significantly higher risks of CV morbidity and mortality for people living in close proximity to major roadways, vs. those living further away. Abundant epidemiological studies now link exposure to vehicular emissions, characterized in many different ways, with CV health endpoints such as cardiopulmonary and ischemic heart disease and circulatory-disease-associated mortality; incidence of coronary artery disease; acute myocardial infarction; survival after heart failure; emergency CV hospital admissions; and markers of atherosclerosis. We identify numerous in vitro, in vivo, and human panel studies elucidating mechanisms which could explain many of these cardiovascular morbidity and mortality associations. These include: oxidative stress, inflammation, lipoperoxidation and atherosclerosis, change in heart rate variability (HRV), arrhythmias, ST-segment depression, and changes in vascular function (such as brachial arterial caliber and blood pressure). Panel studies with accurate exposure information, examining effects of ambient components of vehicular emissions on susceptible human subjects, appear to confirm these mechanisms. Together, this body of evidence supports biological mechanisms which can explain the various CV epidemiological findings. Based upon these studies, the research base suggests that vehicular emissions are a major environmental cause of cardiovascular mortality and morbidity in the United States. As a means to reduce the public health consequences of such emissions, it may be desirable to promulgate a black carbon (BC) PM2.5 standard under the National Ambient Air Quality Standards, which would apply to both on and off-road diesels. Two specific critical research needs are identified. One is to continue research on health effects of vehicular emissions, gaseous as well as particulate. The second is to utilize identical or nearly identical research designs in studies using accurate exposure metrics to determine whether other major PM pollutant sources and types may also underlie the specific health effects found in this evaluation for vehicular emissions

'We've just learnt to put up with it': an exploration of attitudes and decision-making surrounding playing with injury in English professional football

A number of psychological and sociocultural factors have been suggested to influence athletes’ willingness to play despite being injured. Investigation of this phenomenon is undertaken optimally at the time when athletes are injured; however, many studies have relied upon retrospective recall of feelings in individuals following recovery. This study aimed, through semi-structured existential-phenomenological interviews, to explore decision-making and attitudes surrounding playing with injury in professional footballers that were currently injured but continuing to play in matches in the English football leagues. Using deductive qualitative content analysis, cultural, situational and personal moderators that have been theorised to influence playing with injury in professional football were tested. The sample comprised nine professional footballers from three different playing leagues that were identified as playing whilst injured by team physiotherapists. There was a high level of agreement in the findings of this study with previous research. Personal and cultural moderators were stable across participants, and included conforming to the athlete role and operating in a culture where pain has been normalised. Situational factors, however, were unstable and were influenced by playing league, with constraints in squad size being an important influence for lower league players. These professional footballers sought windows of opportunity for treatment and recovery both within the season and at the end of the season. It appeared that a decline in performance, rather than the presence of pain, is used as a critical marker for injury. More research is needed to explore differences in presenteeism practices at different playing levels using larger number of participants