# Health Risk from Toxic Metals in Wild Rice Grown in Copper Mining-Impacted Sediments
###### Abstract  
Northern wild rice is of great dietary and cultural importance to the Native American population in the Upper Peninsula of Michigan. Millions of tons of mine tailings were discharged into Lake Superior and other inland lakes during the copper mining boom in the early 20 th century in this area. This includes L'Anse Bay, located within the Keweenaw Bay Indian Community (KBIC) reservation. Since wild rice restoration is being encouraged by the KBIC, we investigated the distribution of toxic metals in sediments, water, and wild rice and their potential impact on human health from two locations. Sand Point sloughs on L'Anse Bay and a nearby inland lake, Lake Plumbago, were sampled for sediment, water, and wild rice, and the potential human health risk from dietary exposure to toxic metals in wild rice was assessed. Arsenic stood out as the element that had the highest bioaccumulation at both locations. Risk calculations showed that the hazard index (HI) value for wild rice seeds from both sites was high. Data indicate both carcinogenic and non-carcinogenic risks for As from wild rice in Sand Point sloughs and Lake Plumbago, and carcinogenic risks for Cd and Cr at Lake Plumbago.  
legacy mining; Keweenaw Bay; toxic metals; health risk Article  
Health Risk from Toxic Metals in Wild Rice Grown in Copper Mining-Impacted Sediments  
R.D.; [PERSON].;  
[PERSON]; [PERSON]; Health Risk from Toxic Metals in Wild Rice Grown in Copper Mining-Impacted Sediments.  
Applid  
11 February 20221  
into Lake Superior [5]. The fine and coarse fractions of stamp sands gradually migrated toward L'Anse Bay, which is located within the L'Anse Indian Reservation and belongs to the Keweenaw Bay Indian Community (KBIC). The stamp sands adversely impacted the benthic organisms and aquatic food webs [5]. Several reports indicated elevated levels of toxic metals including As, Cd, Cd, Cr, Ni, Zn, Pb, and Fe, in addition to Cu, which is the major contaminant [6; 7; 8].  
These toxic metals exist and accumulate in both water and sediment. The suspension of sediment or metals released from sediments can lead to higher concentrations of metals in water systems. Bioaccumulated toxic metals in animals and humans result in detrimental health effects [9]. While the human health impacts of toxic element uptake and accumulation by white rice are widely studied, understanding the uptake and accumulation of metals by wild rice is limited. [PERSON] and [PERSON] (1995) used commercially available wild rice in the U.S. to analyze metal content and reported high concentrations of Fe, Cu, and Zn, and moderately elevated levels of Pb, Cd, and As [10]. A similar study reported elevated levels of Pb and Cu in wild rice sold in Canada [11]. Elevated levels of As and Pb were reported in a study carried out using wild rice harvested from various locations in north-central Wisconsin by [PERSON] et al. 2000 [12]. Since increasing efforts are being made to restore the wild rice beds in the stamp sand-impacted Keweenaw Bay area, it is important to study the distribution of toxic metals in the Keweenaw Bay sediments and wild rice growing on them vis-a-vis their potential impacts on human health. In this study, our objective was to (1) investigate the concentrations of toxic metals in the sediments, porewater, water column, and wild rice grown in the Sand Point sloughs and a nearby inland lake, Lake Plumbago, in the Upper Peninsula of Michigan, where wild rice restoration and harvesting is increasingly being encouraged by the KBIC, and (2) assess the extent of potential human health risk from dietary exposure to the toxic metals in wild rice.