Traditional Diet and Environmental Contaminants in Coastal Chukotka III: Metals

Abstract

The article is the third in the series of four that present the results of a study on environmental contaminants in coastal Chukotka, which was conducted in the context of a multi-disciplinary investigation of indigenous foodways in the region. The article presents the results of the analysis of metals found in the samples of locally harvested terrestrial, freshwater, and marine biota collected in 2016 in coastal Chukotka. For some species of local fauna and flora, the metals content was demonstrated for the first time. Lead and Hg were low in all foods, while As concentrations were up to four mg/kg ww in fish and marine mammals blubber. Wild plants showed accumulations of Mn (up to 190 mg/kg ww), Al (up to 75 mg/kg ww), Ni, Ba, and Sr. Seaweed contained high levels of As (14 mg/kg) and Sr (310 mg/kg); ascidians (sea squirts) contained Al (up to 560 mg/kg), Cr, and Sr; and blue mussels contained Cd (2.9 mg/kg) and Al (140 mg/kg). Exceedances over the Russian allowable levels were revealed for As, Cd, and Al in different food items. Absence of the established limits for Al and Sr in seafood, and Mn in wild plants and berries, impedes the determination of excess levels. Temporal trends and geographic comparisons of metals in foods have been carried out. The estimated daily intakes (EDIs) of metals by local food consumption were calculated based on the food intake frequencies. Follow-up (15 years after the first study) analyses of Hg, Pb, and Cd concentrations in local foods has not revealed any increase, while a slight decrease tendency was noted for some of the metals in several foods.

Mercury Export Flux in the Arctic Ocean Estimated from 234Th/238U Disequilibria

“…Elevated Hg levels in arctic biota (Dietz et al, 2013, Wang et al, 2018, Dudarev et al, 2019 have been explained by enhanced inorganic Hg inputs to the Arctic Ocean (Outridge et al, 2008, Fisher et al, 2012. Several recent studies aimed at refining Hg inputs from the atmosphere (Schroeder et al, 1998, Soerensen et al, 2016, rivers (Sonke et al, 2018), coastal erosion (Leitch et al, 2007, Schuster et al, 2019, Lim et al, 2020 and other oceans (Cossa et al, 2018, Petrova et al, 2020.…”

Traditional Diet and Environmental Contaminants in Coastal Chukotka I: Study Design and Dietary Patterns

“…The descriptions of the geographic setting, history of the Soviet and post-Soviet developments, recent demographic shifts, utilities and transportation infrastructure, and current living conditions should convey a sense of the challenges that residents in our study region confront in the course of everyday living. The current article is intended to set the stage for the three other articles included in this volume that discuss the legacy POPs [ 1 ] and metals [ 2 ] found in the food samples obtained at our study sites, and the recommendations on the daily intake of foods and other steps to address the threat posed by the presence of environmental contaminants in the Chukotka native diet [ 3 ]. It is important that the data and interpretive ideas presented in the subsequent article are considered in light of the circumstances described here.…”

“…Where relevant, we also draw on the findings from the authors’ earlier research in the region, which spans two decades. Thus, the analyses of the questionnaire (discussed later in this article) and of the contaminants in food samples [ 1 , 2 , 3 ]—all collected in the Chukotkan settlements of Enmelen, Nunligran, and Sireniki—are considered in light of the harvesting and culinary practices, about which members of our team have learned from over 500 Yupik, Chukchi, and Inupiaq residents in the total of 18 communities on both Russian and Alaskan sides of the Bering Strait. The methods employed during Yamin-Pasternak’s ethnographic fieldwork include participant observation, semi-directed interviews, and the development of a public exhibition on the Bering Strait foodways, put together with our community-based collaborators [ 11 ].…”

“…The current article provides an overview of the contemporary foodways in our study region and presents the results of the survey on the consumption of locally harvested foods, carried out in 2016 in the Chukotkan settlements of Enmelen, Nunligran, and Sireniki. With that, this article sets the stage for the analyses of legacy POPs and metals to which the residents become exposed through diet and other practices embedded in the local foodways [ 1 , 2 ] and for the discussion of the Recommended Food Daily Intake Limits (RFDILs) of the food that has been sampled and analyzed in the current study [ 3 ]. Together, articles I–IV, offer the perspectives from the several fields of sciences and humanities represented in our project.…”

“…That is due to the bioaccumulation and biomagnification of POPs and metals in the marine food chain, as well as the lipophilic features of these contaminants. That is the reason for the high exposure to POPs and metals by native people who consume marine mammals [ 1 , 2 ].…”