The concentration-response relationship between daily ambient inhalable particle (particulate matter less than or equal to 10 micro m; PM(10)) concentrations and daily mortality typically shows no evidence of a threshold concentration below which no relationship is observed. However, the power to assess a relationship at very low concentrations of PM(10) has been limited in studies to date. The concentrations of PM(10) and other air pollutants in Vancouver, British Columbia, Canada, from January 1994 through December 1996 were very low: the 50th and 90th percentiles of daily average PM(10) concentrations were 13 and 23 micro g/m(3), respectively, and 27 and 39 ppb, respectively, for 1-hr maximum ozone. Analyses of 3 years of daily pollution (PM(10), ozone, sulfur dioxide, nitrogen dioxide, and carbon monoxide) concentrations and mortality counts showed that the dominant associations were between ozone and total mortality and respiratory and cardiovascular mortality in the summer, and between nitrogen dioxide and total mortality in the winter, although some association with PM(10) may also have been present. We conclude that increases in low concentrations of air pollution are associated with increased daily mortality. These findings may support the notion that no threshold pollutant concentrations are present, but they also raise concern that these effects may not be effects of the measured pollutants themselves, but rather of some other factor(s) present in the air pollution-meteorology mix.
Cites: J Air Waste Manag Assoc. 2000 Jul;50(7):1184-9810939211
Cites: Am J Epidemiol. 2000 Sep 1;152(5):397-40610981451
Cites: J Air Waste Manag Assoc. 2000 Aug;50(8):1481-50011002609
An historical review is made of Antarctic medical practice, which is unique because of the absence of an indigenous population. This review begins with the primitive shipboard practice of doctors accompanying Captain James Cook around 1775 and concludes with the modern era of permanent stations and vast scientific endeavour. The heroic era of Scott, Shackleton, Amundsen and Mawson and the highly mechanized transition period are contrasted with the present day. Medical practice on modern expeditions has reached a high standard, but there is still much to be learned concerning human adaptation. Comment is made on the possible utilization of Antarctica's natural resources bringing increases in polar populations and facilitating the expansion of medical research in the future era of polar medicine.
INTRODUCTION: Over the years town gas has caused many fatal carbon monoxide poisonings. The aim of this paper is to document the circumstances surrounding town gas deaths in Denmark between 1995-1999 and to trace the development of these deaths in recent decades. MATERIALS AND METHODS: A retrospective study of death certificates and report material concerning carbon monoxide deaths in Denmark between 1995-1999 caused by town gas. Of 449 non-fire related carbon monoxide poisonings, 22 (4.9%) were caused by town gas. RESULTS: The deaths consisted of fourteen suicides, six accidents, and two with undetermined manner of death. Ten (71%) of the suicide victims were men and four (29%) were women, with an average age of 48 years (24-82 years); all had turned on two or more gas rings. The accident victims were one man and five women, with an average age of 84 years (77-92 years); all had only turned on one gas ring. CONCLUSION: The number of town gas deaths has been drastically reduced since 1969, which can be explained by the reduced number of town gas installations containing carbon monoxide as well as preventive measures. Most deaths can probably be avoided when the town gas supply is switched to carbon monoxide-free town gas in 2007, but it is important to be aware that incomplete combustion of carbon monoxide-free town gas can still lead to carbon monoxide poisonings.
Exposure to exhaust fumes from combustion engines can lead to carbon monoxide (CO) poisoning. Sea King Rescue helicopter crews are frequently subjected to engine exhaust. This study investigates the extent of CO exposure and potential for intoxication for flight crews during standard operational training procedures.
Over a 2-week period, rescue helicopter flight crews were monitored for exposure to exhaust fumes and clinical symptoms of CO intoxication by means of a written survey and measurements of carboxyhemoglobin saturation (SpCO) with a handheld pulse CO oximeter (RAD-57; Masimo, Irvine, CA). Normal ranges for SpCO were defined as = 4%.
Sixty-nine completed surveys and 138 SpCO measurements of 37 crewmembers were included in the study. Sixty-four percent (n = 44) experienced subjective exposure to engine exhaust during training. Clinical symptoms were reported in 8.6% (n = 6) and included exhaustion (n = 4), headache (n = 1), and nausea (n = 1). Twenty-nine percent (n = 20) showed postflight SpCO levels outside the normal range (= 4%). The maximum postflight SpCO level among all measurements was 7%.
Exposure to engine fumes is common, even more so during open cargo door operations. However, clinical symptoms are infrequent and mild. Toxic SpCO levels were not reached in this study, but approximately one third of postflight SpCO levels were outside the normal range.
Alaska has the highest age-adjusted death rate from unintentional carbon monoxide poisoning in the nation. We conducted a study in five villages to determine carbon monoxide levels and sources. Nearly 10% (10/105) of the homes had elevated levels. Improperly vented propane Paloma water heaters were most commonly responsible and produced the highest levels of carbon monoxide. Other sources were leaking pipes from wood stoves and stoves that had been left on for several hours. We recommend that Paloma water heaters not be used where freezing temperatures create a risk for carbon monoxide poisoning, fires, and explosion. Safety education campaigns should note the risks of Paloma water heaters and defective stove pipes, and the need for increased kitchen ventilation during prolonged cooking. Medical workers need to be informed of the prevalence of carbon monoxide exposures. Homeowners can install carbon monoxide detectors, although expense and false alarms remain barriers to their use.