Ponggol estuary, located on the northeastern coast of Singapore, is heavily impacted by reclamation, dredging, construction and shipping. Tin, lead, nickel, cadmium, copper and zinc in the particulate and dissolved fraction and in sediments were monitored biweekly in the estuary from July 1999 to June 2000. The concentrations of tin, lead, nickel, cadmium, copper and zinc were observed to range...

We compared modern limnological characteristics of three lakes near the world’s northernmost base metal (lead-zinc) mine, Polaris Mine, which operated from 1981 to 2002 on Little Cornwallis Island (Nunavut, Canada), a suite sites Resolute Bay (Qausuittuq), Island. Although both study regions are underlain by broadly similar geology and experience nearly identical climatic conditions, present-da...

Both dietary iron and copper were inversely related to lead absorption as indicated by erythrocyte and kidney lead levels, dietary iron having the greatest effect. Kidney copper values were depressed when dietary iron was low, a condition which was worsened by lead. Lead tended to lower heart cytochrome c oxidase especially when dietary copper was low, but also when dietary copper and zinc were...

Mining activity produces metal sulfide wastes particularly pyrite which remain in the mine long after operations cease. When water percolates through a mine where oxygen is present, a series of chemical reactions occur which produce extremely low pH and high concentrations of toxic sulfate and metal ions. This toxic leachate can cause severe aquatic habitat degradation downstream of the mine. T...

Municipal Solid Waste Incineration (MSWI) fly ash contains significant amounts of leachable metals, and is therefore considered as hazardous waste. The increased amounts of fly ash generated cause environmental issues, management costs and accumulation of valuable metals in landfills. All these factors contribute to an increased interest in recognizing the ash as an urban mining target of metal...

Copper-mine tailings are the residual products after the extraction of precious copper metal from copper ores, and their storage can create numerous environmental problems. Many researchers have used copper-mine tailings for the preparation of geopolymers. This paper studies the enhancement of the cementitious activity of copper-mine tailings in geopolymer systems. First, copper-mine tailings a...

OBJECTIVES Minerals such as zinc, copper, selenium, calcium, and magnesium are essential for normal human development and functioning of the body. They have been found to play important roles in immuno-physiologic functions. The study is to evaluate the distribution and correlation of nonessential (lead) and essential elements in whole blood from 1- to 72-month old children. METHODS The cross...

During its active operation from 1973 to 1990 the Black Angel Mine in West Greenland disposed its tailings in seawater slurry to a fjord. During the disposal between 10 and 30 tons of lead and between 30 and 55 tons of zinc dissolved annually in the receiving sea water. This resulted in a significant pollution of the surrounding marine environment. Other pollution sources, particularly waste ro...