Advances in Methylmercury Toxicology and Risk Assessment

Recent Progress in Nanotechnology-Based Approaches for Food Monitoring

Throughout the food supply chain, including production, storage, and distribution, food can be contaminated by harmful chemicals and microorganisms, resulting in a severe threat to human health. In recent years, the rapid advancement and development of nanotechnology proposed revolutionary solutions to solve several problems in scientific and industrial areas, including food monitoring. Nanotechnology can be incorporated into chemical and biological sensors to improve analytical performance, such as response time, sensitivity, selectivity, reliability, and accuracy. Based on the characteristics of the contaminants and the detection methods, nanotechnology can be applied in different ways in order to improve conventional techniques. Nanomaterials such as nanoparticles, nanorods, nanosheets, nanocomposites, nanotubes, and nanowires provide various functions for the immobilization and labeling of contaminants in electrochemical and optical detection. This review summarizes the recent advances in nanotechnology for detecting chemical and biological contaminations in the food supply chain.

Armed conflict, pollution, and health risks: A risk evaluation of three sources of environmental exposure associated with the conflict in Colombia

Introduction: Armed conflicts affect territories rich in resources and biodiversity. As a result of the environmental damage caused by violent actions, the health of populations can be affected. Objectives: To assess the risks to human health due to environmental degradation associated with three violent actions in the context of the Colombian armed conflict: Pipeline bombing, informal mining with mercury, and spraying of illicit crops with glyphosate. Materials and methods: We conducted a quantitative evaluation of the risks to individual health associated with armed conflict activities using methodologies focused on the routes of pollutants dispersion, their concentrations in the environment, the exposure of the individuals, and the risks of carcinogenic and non-carcinogenic effects. Results: The risk assessment of the armed conflict-related actions under study evidenced intolerable carcinogenic risk and unacceptable non-carcinogenic risk due to the consumption of water and fish contaminated by polycyclic aromatic hydrocarbons (PAH), mercury, and glyphosate. Conclusions: The study reiterates the inextricable connections existing among the environment, society, and health, as well as the implications of environmental violence for the public health of vulnerable population groups and, in general, for the well-being of all living beings affected by the armed conflict.

Regionally representative hair mercury levels in Canadian First Nations adults living on reserves

OBJECTIVE

The primary objective of this participatory study was to assess the current body burden of mercury among First Nations adults.

METHODS

The First Nations Food, Nutrition and Environment Study (2008-2018) collected regionally representative data from First Nations adults living on reserves south of the 60th parallel. Mercury was analyzed in hair as a preferred biomarker for prolonged exposure. Hair samples, a 5 mm bundle cut from the occipital region, were collected from the participants who gave consent and measured for total mercury concentrations using cold vapor atomic fluorescence spectrophotometry.

RESULTS

In total, 3404 First Nations adults living in 92 communities provided hair samples. This represents 52.5% of the respondents to the household surveys. The mean hair mercury concentrations were 0.56 μg/g among all participants and 0.34 μg/g among women of childbearing age (WCBA). There were 64 exceedances of Health Canada's mercury biomonitoring guidelines (44 WCBA, 8 women aged 51+ years, 3 men aged 19-50 years, and 9 men aged 51+ years).

CONCLUSION

Current mercury exposure no longer presents a significant clinical health risk in most of the First Nations population south of the 60th parallel across Canada. However, mercury exposure continues to be an ongoing environmental public health concern that requires continued monitoring and assessment. Women of childbearing age (19-50 years) and older individuals living in northern ecozones and Quebec have higher mercury exposures, often exceeding Health Canada's guidelines. Careful risk communication and risk management programs need to focus on northern ecozones and Quebec.

A New Low-Cost and Reliable Method to Evaluate the Release of Hg0 from Synthetic Materials

Mercury is a toxic and noxious element and is the only metal that naturally occurs as gas. One of the most challenging topics (included in the United Nations Minimata convention) is to understand the adsorption–release processes of manmade materials (e.g., concrete, bricks, tiles, painting). Adsorption of Hg by construction and demolition waste materials has recently been studied, but investigations on how much Hg0 can be released from these products are rather poor. The abandoned mining site of Abbadia San Salvatore (Siena, central Italy) where, for about one century, cinnabar was roasted to produce liquid mercury, is known for the high concentrations of (i) Hg0 in edifices and structures and (ii) total and leachate Hg in synthetic materials. In the present paper, a new, simple and low-cost method to measure the amount of GEM (Gaseous Elemental Mercury) released from anthropic materials (concrete, wall rocks, and tiles) located in the Hg0-rich environments of the former mining site, is proposed. The efficiency of a specific paint that was supposed to act as blocking agent to Hg0 was also tested.

Screening for Elevated Blood Lead Levels and Related Risk Factors among Thai Children Residing in a Fishing Community

The present study explored environmental and behavioral factors associated with elevated blood lead (Pb) levels in 311 children (151 girls and 160 boys), aged 3–7 years, who lived in a coastal fishing community of the Pakpoon Municipality, Nakhon Si Thammarat, Thailand. The geometric mean for blood Pb was 2.81 µg/dL, ranging between 0.03 and 26.40 µg/dL. The percentage of high blood Pb levels, defined as blood Pb ≥ 5 µg/dL, was 10.0% in boys and 13.9% in girls. Parental occupation in producing fishing nets with lead weights was associated with a marked increase in the prevalence odds ratio (POR) for high blood Pb (POR 17.54, 95%; CI: 7.093, 43.390; p < 0.001), while milk consumption was associated with 61% reduction in the POR for high blood Pb (POR 0.393, 95%; CI: 0.166, 0.931; p = 0.034). High blood Pb was associated with an increased risk for abnormal growth (POR 2.042, 95%; CI: 0.999, 4.174; p = 0.050). In contrast, milk consumption was associated with a 43% reduction in POR for abnormal growth (POR 0.573, 95%; CI: 0.337, 0.976; p = 0.040). After adjustment for age, the mean (standard error of mean, SE) values for blood Pb were 6.22 (0.50) μg/dL in boys and 6.72 (0.49) μg/dL in girls of parents with an occupation in making fishing nets with lead weights. These mean blood Pb values were respectively 2.3 and 2.5 times higher than similarly aged boys and girls of parents with other occupations. These data are essential for setting surveillance and programmes to prevent toxic Pb exposure, especially in children of coastal fishing communities in southern Thailand.