Evaluation of heavy metal accumulation in soils and plants is of environmental importance due to their health effects on humans and other biota. Phytoremediation is an emerging technology that can stabilize or remove heavy metals in soil utilizing metal tolerant plant species (metallophytes). The objectives of this study were to: (1) assess a Superfund site, and a lead-acid battery dump for concentrations of soil lead (Pb) and cadmium (Cd); (2) assess the various chemical fractions of Pb and Cd at both sites; (3) identify native herbaceous vegetation surviving in the contaminated soils; and (4) evaluate plant uptake of Pb and Cd. Soil Pb and Cd concentrations at the Superfund site averaged 55,480 and 8.5 mg/kg, respectively. Soil Pb at the Superfund site occurred primarily in the carbonate, sulfide/residual, and organic chemical fractions (41.6, 28.6, and 26.7, respectively). Soil Pb and Cd concentrations at the dump site averaged 29,400 and 3.9 mg/kg, respectively. Soil Pb occurred mostly in the organic and carbonate fractions as 48.5 and 42.5% respectively. Plant uptake of Pb at both sites ranged from non-detectable (Agrostemma githago, Plantago rugeli, Alliaria officinalis shoots), to 1800 mg/kg (Agrostemma githago root). Cd uptake was maximal in Taraxacum officinale at 15.4 mg/kg (Superfund site). In the majority of plants studied, root Pb and Cd content was higher than for shoots (>_65%). Tissue and soil fractions yielded r2 of 0.61 and 0.57 for the soluble and carbonate-Pb fractions, respectively. The plants with the greatest tissue concentrations of Pb and Cd were predominantly herbaceous species, some of which produce sufficient biomass to be practical for phytoremediation technologies. / Department of Natural Resources and Environmental Management

Phytoextraction is an innovative method that can be implemented to remove lead (Pb), cadmium (Cd), and zinc (Zn) from contaminated soil. A two-year field and growth chamber study was conducted to determine the effectiveness of several soil amendments in the phytoextraction or stabilization of Pb, Cd and Zn. Field plots were established at the Memorial Drive Dump site (Muncie, IN). Amendments included composted municipal solid waste (MSW) (25 Mg/ha), dried sewage sludge (SS) (25 Mg/ha), citric acid (2 mmol/kg soil), ethylenediaminetetraacetic acid (EDTA) (2 mmol/kg soil), and a control. A mixed grass crop was capable of survival and growth in the contaminated soil; in contrast, Helianthus annuus (sunflower) and Ambrosia artemisiifolia (ragweed) failed to become established. Soil Pb and Zn occurred primarily in the carbonate, organic-bound and residual forms (23.1%, 31.8%, and 44.4%, Pb, respectively and 11.4%, 26.5%, and 60.2% Zn, respectively). Soil Cd occurred primarily in the soluble, carbonate, and residual forms (21.8%, 21.3%, and 27.4%, respectively). In a growth chamber leaching study, soil Pb was most rapidly leached from the 0.1 M EDTA treatment (51.7 mg Pb over 200 pore volumes); the 0.001M resulted in the lowest leaching. Soil Pb was most rapidly leached using 0.1 M HEDTA (52.1 mg Pb over 200 pore volumes). The 0.001 M HEDTA rate resulted in lowest Pb leaching. Addition of an NPK solution resulted in minimal Pb leached. The MSW and dried sludge treatments resulted in the greatest dry matter production on the plots. Dry matter production was significantly (p >0.05) higher in the MSW (1.09 MT/ha) and SS (95 MT/ha) treatments. Addition of EDTA, citric acid and MSW significantly (p < 0.05) increased the amount of Cd uptake into plant tissue. The study also demonstrated the ability of vegetation to establish and grow on toxic soil and to uptake Pb, Cd, and Zn. / Department of Natural Resources and Environmental Management

Lethal toxicity values (96 h LC50; mg Cd/L) for the test species were similar: Lepomis cyanellus, 11.52; Notropis lutrensis, 6.62; Pimephales promelus, 3.58. However the effects of cadmium concentration and exposure time on temperature tolerance varied between species. Neither cadmium concentration nor exposure time had a significant effect on the CTM of green sunfish. Both cadmium concentration and exposure time had a significant effect on the CTMs of red shiners and fathead minnows. By day 10 mean CTMs were 2.3 t- 4.5 C (red shiners) and 4.2 to 5.7 C (fathead minnows) lower than control CTM. These results suggest a potential problem in cadmium contaminated systems for high environmental temperatures to stress or kill fish.

Heavy metal bioaccumulation in aquatic organisms may occur through direct or indirect uptake routes. Research indicates that the significance of uptake route varies with contaminant and organism exposed. The relative importance of different metal sources in aquatic systems was investigated by exposing freshwater snails to dietary or dissolved sources of cadmium. Snails were exposed to control, contaminated food only, contaminated water only, and contaminated food and water treatments. During the 15-day exposure, samples were taken to determine Cd concentration in snail soft tissue, snail shell, algal food, and overlying water. Analyses of snail soft tissue and shells indicate that exposure route significantly affects Cd concentrations in the tissues. In both cases, dissolved Cd is the primary contributor to metal body burden.

Effects of episodic exposures have gained attention as the regulatory focus of the Clean Water Act has shifted away from continuous-flow effluents. Standardized laboratory toxicity tests require that exposure be held constant. However, this approach may not accurately predict organism responses in the field following episodic exposures such as those associated with rain-driven runoff events or accidental pollutant discharge. Using a modified version of the 7-day short-term chronic test recommended by the US Environmental Protection Agency, Ceriodaphnia dubia were exposed to copper or cadmium for durations ranging from 1 minute to 24 hours. In addition, adult reproductive recovery and effects on second generation individuals was assessed following select copper exposures. Finally, cadmium exposures were compared in reconstituted hard water (RHW) and municipal treated wastewater effluent (TWE). Following exposure, organisms were transferred to clean RHW or TWE and maintained for the remainder of the test. No- and lowest observed effect concentrations (NO- and LOECs) increased logarithmically with respect to logarithmic decreases in duration regardless of metal, endpoint or water type. Effective concentrations of cadmium however, were usually higher than those of copper, especially in TWE. LOECs for C. dubia survival following 24-hour and 5-minute exposures to copper were 116 and 417 µg/L, respectively. LOECs for fecundity were 58 and 374 µg/L, respectively. Neonate production of first generation adult C. dubia appeared to recover from pulsed copper exposure upon examination of individual broods. Cumulative mean neonate production however, showed almost no signs of recovery at exposure durations ≥3 hours. Pulse exposure to copper also resulted in diminished fecundity of unexposed second generation individuals. Such effects were pronounced following parental exposure for 24 hours but lacking after parental exposures ≤3 hours. LOECs for C. dubia survival following 24-hour and 5-minute exposures to cadmium in RHW were 44 and 9000 µg/L, respectively. LOECs for fecundity were 16 and 5000 µg/L, respectively. In TWE, LOECs for C. dubia survival were 83 and >10,000 µg/L, respectively. LOECs for fecundity in TWE were 48 and 7000 µg/L, respectively. Runoff pollution is site and event specific, however, data presented herein may be useful as a predictive tool under various conditions.

Graduation date: 1993

The aim of this study was to investigate the cadmium (Cd) exposure level from traditional food in Fort Resolution, Northwest Territories. Cd concentration in the liver and kidney of caribou and moose exceeded the action level (1 $ mu$g/g) established by Agriculture Canada, but the frequencies of consumption of these foods were relatively low. Cd intakes from traditional food ranged from 0.01 to 1713 $ mu$g/day/person. Average Cd intakes from traditional food were estimated to be 10% and 6% of the Provisional Tolerable Weekly Intake (PTWI), 7 $ mu$g/kg body weight/person, for women and men, respectively. The major contributors to the total Cd intake on a population basis were moose liver for women, and flesh of moose and caribou for men. The average Cd inhaled from cigarette smoking was 21.1 $ pm$ 9.1 $ mu$g/day/person. Total Cd intakes from traditional food and smoking were estimated to be 24% and 20% of the PTWI for women and men, respectively. The total Cd intakes of smokers and nonsmokers were significantly different (p $<$ 0.001). The total Cd intake via market and traditional food, and cigarette smoking was 246.4 $ mu$g/week which was lower than the PTWI, 500 $ mu$g/week. Another objective of this study was to investigate an effect of food preparation on Cd speciation in food. (Abstract shortened by UMI.)

Thesis (M. Sc. Agriculture (Animal Production)) -- University of Limpopo, 2021 / The study was carried out to determine the concentration levels of mercury (Hg), lead (Pb), cadmium (Cd), chromium (Cr), nickel (Ni) and zinc (Zn) in water, soil, witbuffels grass and meat of goats reared along the river banks of Middle Olifants (Mogalatsana village) and Mogalakwena (Papegaai village) rivers. The samples were collected from the river water, soils along the river banks, grass grown along the river banks and male Pedi goats reared in Mogalatsana and Papegaai villages. The samples were analysed for the selected heavy metals with an inductively coupled plasma mass spectroscopy (ICP-MS). Data was analysed as in a complete randomised design. The results of selected heavy metals in water of both rivers ranged from 0.00 mg/litre of water (Ni and Cr) to 0.04 mg/litre of water (Hg). The concentration levels of selected heavy metals in water were similar (P>0.05) for Middle Olifants and Mogalakwena rivers. The concentration levels of selected heavy metals in the soils along the banks of Middle Olifants and Mogalakwena rivers ranged from 0.00 mg/kg DM soil (Hg and Cd) to 63.70 mg/kg DM soil (Cr). There were similar (P>0.05) concentration levels of selected heavy metals in the soils along the banks of Middle Olifants and Mogalakwena rivers. Heavy metal concentration levels in the witbuffels grass grown along the banks of Middle Olifants and Mogalakwena rivers ranged from 0.00 mg/kg DM of grass (Hg and Cd) to 5.05 mg/kg DM of grass (Zn). Similar (P>0.05) concentrations of selected heavy metals were observed in witbuffels grass grown along the banks of Middle Olifants and Mogalakwena rivers. However, the concentration levels of Zn, Pb and Cd in water from both sites were above internationally maximum permissible levels, indicating that the water from these rivers was not safe for drinking by humans and animals. The concentration levels of Ni and Pb in soils from both sites were above internationally recommended maximum permissible limits. Similarly, chromium concentration levels in witbuffels grass from both sites were above the recommended maximum permissible limits for livestock, indicating that the grass was not safe for consumption by livestock. It is recommended that further studies be conducted to ascertain these findings. Blood, liver, kidney and meat samples of yearling male Pedi goats grazing along the banks of Middle Olifants river (Mogalatsana village) had similar (P>0.05) Cr, Cd, Hg, Ni and Pb concentration levels, respectively. However, goat liver samples had higher (P<0.05) Zn concentrations than meat, kidney and blood samples. Samples of goat v meat contained higher (P<0.05) Zn concentrations than those of kidneys and blood. Similarly, goat kidney samples contained more (P<0.05) Zn than blood samples. Blood, liver, kidney and meat samples of Pedi goats grazing along the banks of Mogalakwena river (Papegaai village) contained similar (P>0.05) concentration levels of Cr, Cd, Hg, Ni and Pb, respectively. However, goat meat samples contained higher (P<0.05) Zn concentrations than liver, kidney and blood samples. Samples of goat liver contained higher (P<0.05) Zn concentration levels than kidney and blood samples. Similarly, goat kidney samples contained more (P<0.05) Zn than blood samples. Meat, blood, liver and kidney samples of male Pedi goats raised in Mogalatsana and Papegaai villages had similar (P>0.05) chromium, cadmium, mercury, nickel and lead concentrations, respectively. However, liver and kidney samples of goats from Mogalatsana village had higher (P<0.05) zinc levels than those from Papegaai village. Blood and meat samples of goats from Papegaai village had higher (P<0.05) zinc levels than those from Mogalatsana village. The concentration levels of Zn, Ni, Pb, Cr and Cd in the blood, liver, kidney and meat samples of male Pedi goats reared along the banks of Middle Olifants and Mogalakwena rivers were within the maximum permissible levels for human consumption. Mercury concentration levels in liver, kidney and meat samples of the goats were within the maximum permissible levels for human consumption. However, mercury concentration levels in the blood of goats grazing along the banks of Middle Olifants and Mogalakwena rivers were above the maximum permissible limit of 0.2 mg/litre of blood. It was concluded that meat, livers and kidneys of the goats were fit for human consumption. However, blood from these goats was not fit for human consumption.

No description available.