Influence of mercury exposure on blood pressure, resting heart rate and heart rate variability in French Polynesians: a cross-sectional study

<p>Abstract</p> <p>Background</p> <p>Populations which diet is rich in seafood are highly exposed to contaminants such as mercury, which could affect cardiovascular risk factors</p> <p>Objective</p> <p>To assess the associations between mercury and blood pressure (BP), resting heart rate (HR) and HR variability (HRV) among French Polynesians</p> <p>Methods</p> <p>Data were collected among 180 adults (≥ 18 years) and 101 teenagers (12-17 years). HRV was measured using a two-hour ambulatory electrocardiogram (Holter) and BP was measured using a standardized protocol. The association between mercury and HRV and BP parameters was studied using analysis of variance (ANOVA) and analysis of covariance (ANCOVA)</p> <p>Results</p> <p>Among teenagers, the high frequency (HF) decreased between the 2^ndand 3^rdtertile (380 vs. 204 ms², p = 0.03) and a similar pattern was observed for the square root of the mean squared differences of successive R-R intervals (rMSSD) (43 vs. 30 ms, p = 0.005) after adjusting for confounders. In addition, the ratio low/high frequency (LF/HF) increased between the 2^ndand 3^rdtertile (2.3 vs. 3.0, p = 0.04). Among adults, the standard deviation of R-R intervals (SDNN) tended to decrease between the 1^stand 2^ndtertile (84 vs. 75 ms, p = 0.069) after adjusting for confounders. Furthermore, diastolic BP tended to increase between the 2^ndand 3^rdtertile (86 vs. 91 mm Hg, p = 0.09). No significant difference was observed in resting HR or pulse pressure (PP)</p> <p>Conclusions</p> <p>Mercury was associated with decreased HRV among French Polynesian teenagers while no significant association was observed with resting HR, BP, or PP among teenagers or adults</p

Indicators of ocean health and human health: developing a research and monitoring framework

This is the final version of the article. Available from NIEHS via the DOI in this record.We need to critically assess the present quality of the marine ecosystem, especially the connection between ecosystem change and threats to human health. In this article we review the current state of indicators to link changes in marine organisms with eventual effects to human health, identify research opportunities in the use of indicators of ocean and human health, and discuss how to establish collaborations between national and international governmental and private sector groups. We present a synthesis of the present state of understanding of the connection between ocean health and human health, a discussion of areas where resources are required, and a discussion of critical research needs and a template for future work in this field. To understand fully the interactions between ocean health and human health, programs should be organized around a "models-based" approach focusing on critical themes and attributes of marine environmental and public health risks. Given the extent and complex nature of ocean and human health issues, a program networking across geographic and disciplinary boundaries is essential. The overall goal of this approach would be the early detection of potential marine-based contaminants, the protection of marine ecosystems, the prevention of associated human illness, and by implication, the development of products to enhance human well-being. The tight connection between research and monitoring is essential to develop such an indicator-based effort.This work was funded by the National Institute of Environmental Health Sciences, the Intergovernmental Oceanographic Commission (UNESCO), and the Bermuda Biological Station for Research, Inc. (contribution 1615)

A preliminary study of mercury exposure and blood pressure in the Brazilian Amazon

BACKGROUND: Fish is considered protective for coronary heart disease (CHD), but mercury (Hg) intake from fish may counterbalance beneficial effects. Although neurotoxic effects of methylmercury (MeHg) are well established, cardiovascular effects are still debated. The objective of the present study was to evaluate blood pressure in relation to Hg exposure and fish consumption among a non-indigenous fish-eating population in the Brazilian Amazon. METHODS: The study was conducted among 251 persons from six communities along the Tapajós River, a major tributary of the Amazon. Data was obtained for socio-demographic information, fish consumption, height and weight to determine body mass index (BMI), systolic and diastolic blood pressure, and Hg concentration in hair samples. RESULTS: Results showed that overall, systolic and diastolic blood pressure, were relatively low (mean: 113.9 mmHg ± 14.6 and 73.7 mmHg ± 11.0). Blood pressure was significantly associated with hair total Hg (H-Hg), age, BMI and gender. No association was observed between fish consumption and blood pressure, although there were significant inter-community differences. Logistic regression analyses showed that the Odds Ratio (OR) for elevated systolic blood pressure (≥ 130 mmHg) with H-Hg ≥ 10 μg/g was 2.91 [1.26–7.28], taking into account age, BMI, smoking, gender and community. CONCLUSION: The findings of this preliminary study add further support for Hg cardiovascular toxicity