Heavy metal contamination of urban soils and street dusts in Hong Kong

This public health statement tells you about cadmium and the effects of exposure to it.The Environmental Protection Agency (EPA) identifies the most serious hazardous waste sites in the nation. These sites are then placed on the National Priorities List (NPL) and are targeted for long-term federal clean-up activities. Cadmium has been found in at least 1,014 of the 1,669 current or former NPL sites. Although the total number of NPL sites evaluated for this substance is not known, the possibility exists that the number of sites at which cadmium is found may increase in the future as more sites are evaluated. This information is important because these sites may be sources of exposure and exposure to this substance may be harmful.When a substance is released either from a large area, such as an industrial plant, or from a container, such as a drum or bottle, it enters the environment. Such a release does not always lead to exposure. You can be exposed to a substance only when you come in contact with it. You may be exposed by breathing, eating, or drinking the substance, or by skin contact.If you are exposed to cadmium or cadmium compounds, many factors will determine whether you will be harmed. These factors include the dose (how much), the duration (how long), and how you come in contact with it. You must also consider any other chemicals you are exposed to and your age, sex, diet, family traits, lifestyle, and state of health.

Toxicological Profile for Cadmium

Heavy metals and metalloids in soils are derived from the soil parent material (lithogenic source) and various anthropogenic sources, most of which involve several metal(loid)s. There are many different anthropogenic sources of heavy metal(loid) contamination affecting both agricultural and urban soils. However, localised contamination from a predominant single source, such as a metal smelter can have a marked effect on soils, vegetation and possibly also on the health of the local population, especially in countries where there are inadequate emission controls and soil quality standards. In general, soils at industrial sites can have distinct groups of heavy metal(loid) contaminants, which depend on the respective industries and their raw materials and products. Soils in all urban areas are generally contaminated with lead (Pb), zinc (Zn), cadmium (Cd) and copper (Cu) from traffic, paint and many other non-specific urban sources. Although the heavy metal(loid) composition of agricultural soils tends to be more closely governed by the parent material, inputs from sources such as deposition of long-distance, atmospherically-transported aerosol particles from fossil fuel combustion and other sources, organic material applications and contaminants in fertilisers can also be significant. Removal of Pb from petrol and paints, changes in the type and structure of industries and strict regulations on atmospheric emissions and waste water discharges have resulted in a general reduction in the loads of heavy metal(loid)s reaching soils in many countries. However, historic contamination still affects soils in many areas and may have impacts for decades or even centuries afterwards.

Sources of Heavy Metals and Metalloids in Soils

http://ira.lib.polyu.edu.hk/bitstream/10397/2559/1/B44%20HKI%20Soil%20Paper%202005.pdf

Metal contamination in urban, suburban, and country park soils of Hong Kong: a study based on GIS and multivariate statistics.

Soils: their implications to human health

Lead intake and blood lead in two-year-old U.K. urban children

The Shipham report. An investigation into cadmium contamination and its implications for human health. Metal availability.

Dietary surveys on a population at Shipham, Somerset, United Kingdom.

1 Factors affecting blood lead concentrations in three groups of children of different ethnic origin have been investigated.2 Dietary lead intakes were similar for the three groups, the average lead intakes lay in the range 110-150 μg/week.3 Blood lead concentrations were not related to ethnic origin when the effect of other factors was allowed for.4 Children who washed their hands before eating had significantly lower blood lead concentrations than those who did not.

G.A. Smart

Papers

Lead intake and blood lead in two-year-old U.K. urban children

The Shipham report. An investigation into cadmium contamination and its implications for human health. Metal availability.

Dietary surveys on a population at Shipham, Somerset, United Kingdom.

Blood Lead Concentrations and Lead Intake in Children of Different Ethnic Origin

Intakes of metal