Error analysis applied to indirect methods for precipitation acidity

The historical increase in the acidity of precipitation in northern Europe has been monitored by direct measurements of pH and titrations of acidity. Indirect methods such as conductivity and charge balances as well as chemical source models have been used to confirm the measured acidities. In the absence of historical records of direct measurements of acidity in precipitation in the United States, indirect methods have been applied to available data on the composition of rainwater to quantify the acidity. Unfortunately, the indirect methods are sensitive to small errors in certain pH regions. The effects of random errors in major ion concentrations as well as the systematic errors due to the exclusion of trace metal and organic ions are shown to be largest around pH 5.6 in the charge balance and chemical source strength calculations and largest around pH 6.1 for the conductivity balance method. Estimates of the uncertainty in historical mean values of precipitation ion concentrations are used to calculate upper and lower bounds on the acidity of rainwater in the United States before 1970. The trend of increasing acidity of precipitation in the northeastern United States is still evident after applying error analysis

Association between dental factors and mortality

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Immunologic burden links periodontitis to acute coronary syndrome

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Missing Teeth Predict Incident Cardiovascular Events, Diabetes, and Death

Periodontitis, the main cause of tooth loss in the middle-aged and elderly, associates with the risk of atherosclerotic vascular disease. The objective was to study the capability of the number of missing teeth in predicting incident cardiovascular diseases (CVDs), diabetes, and all-cause death. The National FINRISK 1997 Study is a Finnish population-based survey of 8,446 subjects with 13 y of follow-up. Dental status was recorded at baseline in a clinical examination by a trained nurse, and information on incident CVD events, diabetes, and death was obtained via national registers. The registered CVD events included coronary heart disease events, acute myocardial infarction, and stroke. In Cox regression analyses, having >= 5 teeth missing was associated with 60% to 140% increased hazard for incident coronary heart disease events (P = 9 missing teeth. No association with stroke was observed. Adding information on missing teeth to established risk factors improved risk discrimination of death (P = 0.0128) and provided a statistically significant net reclassification improvement for all studied end points. Even a few missing teeth may indicate an increased risk of CVD, diabetes, or all-cause mortality. When individual risk factors for chronic diseases are assessed, the number of missing teeth could be a useful additional indicator for general medical practitioners.Peer reviewe