The types of mineral mining at the selected mine
areas were two copper–lead–zinc mines and two gold
mines (Fig. 1). They were active mines about from
early until late in the 1900s. Although gold mine has
never been reported to cause Cd disease unlike the
copper–lead–zinc mine, nevertheless, we selected
gold mines because the nearby residents of mines are
concern about health effects due to metal exposure
from abandoned mine regardless of the type of mining,
and gold mine is most common type of mine in Korea.
The mining and smelting ceased in 1970s and, upon
closure, large amounts of mine waste was left behind
without any proper environmental safeguards. The
unprotected mining waste has been dispersed down the
slope by wind and water as a point source pollution of
the vicinity of this mine. As there is no facility
providing the public water supply around the mine
area, the streams nearby the mine tailings are the
source of drinking water for the inhabitants. Pollution
prevention projects for these mines were conducted
during 2007–2009. The population of these mines
were 498, 307, 298, and 774 people, respectively. The
control site was a typical rural area (approximately
500 residents), and there were no mining sites within a
10 km radius (Table 1).
We collected data for studying the mines with Cd
concentration in environmental media, crops, and
biomarkers in blood and urine. The Cd concentrations
in environmental media were soil (n = 570), and
drinking water (n = 52) such as village water supply
type and ground water. The types of agricultural crops
were rice (Oryza sativa L.) (n = 98) and corn (Zea
mays L.) (n = 27). We collected the Cd levels of
blood (n = 752) and urine (n = 730) for residents
who have lived at least 10 years in the study mine
vicinity or control areas. In addition, we collected data
for Cd levels in the ambient air (n = 50) around study
areas using ‘National Ambient Air Monitoring Database
(KMOE 2008c) for human exposure estimation through multimedia and multi-pathways. All collected
data were measured according to the ‘National Standard
Operation Protocols’ for environmental samples
and human bio samples. The total concentration of Cd
was determined by acid digestion method and ICPAES
and ICP-MS instrument. The chemical analytical
results of the cited studies were performed by quality
control system, which includes reagent blanks, replicate
samples, and certified international reference
materials (e.g., CRM for water, HRM1 and HRM2 for
soil, HRM12 and HRM 14 for plants). The precision
and bias of chemical and analysis were 10 %,
respectively.