The association of particulate air metal concentrations with heart rate variability.

Abstract

Numerous studies show an association between particulate air pollution and adverse health effects. Particulate matter is a complex mixture of elemental carbon, ammonium, sulfates, nitrates, organic components, and metals. The mechanisms of action of particulate matter less than or equal to 2.5 micro m in mean aerodynamic diameter (PM(2.5)), as well as the constituents responsible for the observed cardiopulmonary health effects, have not been identified. In this study we focused on the association between the metallic component of PM(2.5) and cardiac autonomic function based on standard heart rate variability (HRV) measures in an epidemiologic study of boilermakers. Thirty-nine male boilermakers were monitored throughout a work shift. Each subject wore an ambulatory electrocardiogram (Holter) monitor and a personal monitor to measure PM(2.5). We used mixed-effects models to regress heart rate and SDNN index (standard deviation of the normal-to-normal) on PM(2.5) and six metals (vanadium, nickel, chromium, lead, copper, and manganese). There were statistically significant mean increases in the SDNN index of 11.30 msec and 3.98 msec for every 1 micro g/m(3) increase in the lead and vanadium concentrations, respectively, after adjusting for mean heart rate, age, and smoking status. Small changes in mean heart rate were seen with all exposure metrics. The results of this study suggest an association between exposure to airborne metals and significant alterations in cardiac autonomic function. These results extend our understanding of the adverse health effects of the metals component of ambient PM(2.5).

Source location of air pollution and cardiac autonomic function: Trajectory cluster analysis for exposure assessment

“…Other studies have also reported that specific components of particles are associated with cardiovascular health outcomes. Magari et al (2002) observed significant increases in SDNN in relation to lead and vanadium concentrations in a healthy occupational cohort. In a recent population-based study, O'Neill et al (2005) also found independent effects of sulfate and BC on depressed vascular reactivity among patients with diabetes.…”

“…These physiologic effects may vary according to the physical and chemical characteristics of the pollutants. Previous studies have evaluated whether certain components of airborne particles, such as transition metal elements, black carbon (BC), and/or sulfate (SO 4 2À ) are responsible for health effects observed in epidemiologic research (Godleski et al, 2000;Laden et al, 2000;Magari et al, 2002;O'Neill et al, 2005;Schwartz et al, 2005). A panel study performed in Boston observed a significant association between BC, a marker of traffic particles, and decreased heart rate (HR) variability (HRV), a marker of cardiac autonomic dysfunction .…”

Cardiac autonomic activity in methylmercury neurotoxicity: 14-year follow-up of a Faroese birth cohort

“…The paucity of information is perhaps not surprising, given the substantial age-dependency of the HRV parameters that might complicate interpretation of cross-sectional studies. Studies of adults with occupational exposure to neurotoxicants [21][22][23][24][25][26][27][28] clearly show that HRV may be affected by chemical exposures that damage the nervous system. However, effects on children would be difficult to predict from studies conducted in adults.…”

“…[17][18][19][20] Abnormalities have also been documented after exposure to neurotoxic agents, such as MeHg, mercury vapor, other metals, certain solvents, and nerve gases. [21][22][23][24][25][26][27][28] In most cases, the CVRR was apparently affected mainly through a relative depression of parasympathetic activity. 21 In particular, a decreased HRV in adult patients that had been born with congenital MeHg poisoning appeared to be mainly due to parasympathetic hypofunction.…”

Cardiovascular Toxicities Upon Manganese Exposure

“…Based on the clinical data, these researchers conclude that Mn exposure interferes with parasympathetic nerve function; the cardiovascular autonomic nervous system may serve as a target for Mn toxicity (51). Other evidence that supports Mn toxicity on the autonomic nerve system comes from a study conducted in 39 male boilermaker construction workers (52). It should be noted that some airborne particulates, with or without the presence of Mn, may have a nonspecific effect on the autonomic nervous system.…”