A History of Global Metal Pollution

摘要

Air pollution is often regarded as the product of modern technological development. In fact, environmental pollution caused by heavy metals began with the domestication of fire: The deposition of small amounts of trace metals released during the burning of firewood altered the' metal levels in the cave environment. With the discovery of mining and metal-working techniques in ancient times, the close link between metals, metal pollution, and human history was formed. Mining and trade of mineral resources became a key feature of the early economy, and metal recovery techniques attained status as a barometer of technological advancement for ancient cultures. During the time of the Roman Empire, large quantities of heavy metals, especially Pb (80,000 to100,000 metric tons per year), Cu (15,000 tons/year), Zn (10,000 tons/year), and Hg (>2 tons/year), as well as Sn and Zn, were required to sustain the high standard of living (1-3). Although the mines were operated on a small scale, uncontrolled smelting of large quantities of ores in open fires resulted in substantial emissions of trace metals to the atmosphere. Emissions of toxic metals were serious enough to draw the attention of a number of ancient authors and may have been responsible for the interdiction of mining operations in Italy and near some ancient cities (4). The influence of ancient mines and smelters on air quality on a global scale is now documented in the report by Hong et al. on page 246 of this issue (2).