Hazard to health after lead poisoning

Hazard to health after lead poisoning

1. Lead poisoning is especially hazardous to the growth of nerves of unborn children and born children, and will severely damage their learning ability and nervous system;

2. The lead content in blood in children exceeds more than 40μg/dl, and there will be difficult in formation of haemoglobin, which may lead to anemia.

3. Lead will hurt kidneys.

4. After lead poisoning, it will lead to the disorder of the nervous system and the production system.

Lead poisoning means heavy metal poisoning, which will not be excreted out of human body, and will be gradually accumulated. It is specified by the American Vocational Safety and Health Control Department that lead content in human body should be controlled to 50μg/dl or even lower. Those who want to give birth to children should control the content to below 30μg/dl.

Access to lead poisoning

1． In daily work, human body absorbs lead or other compounds through absorbing, breathing and taking food by skin.

2． It does hazard to human body by the drinking water system.

Pb+O2→PbO

PbO+H2SO4→PbSO4+H2O

PbO+2HNO3→Pb(NO3)2+H2O

PbO+2HCI→PbCI2+ H2O

After electronic products and industrial trash are directly embedded underground, when it rains, as rainwater is generally acidic water (containing elements of sulfate, nitrate and hydrochloride), and lead in the used electronic products will perform chemical reaction with acid substances in acid rain to generate toxic lead compounds. Its reaction formulas are:

Pb+O2→PbO

PbO+H2SO4→PbSO4+H2O

PbO+2HNO3→Pb(NO3)2+H2O

PbO+2HCI→PbCI2+ H2O

However, toxic lead compounds become soluble in acid water. If the solubility of Pb(NO3)2 in water is 565 g/L (20℃), and rain water is the source of underground water, which is also the major source of our drinking water, finally lead accesses to the water supply system to lead to poisoning.

EU’s RoHS Directive

　　Since July 1, 2006, those electronic and electric products set forth under the used electronic and electric equipment directives enter the European market, there may not be 6 harmful substances as mentioned in RoHS (including lead and lead compounds) as shown in the table below.

The principal objective is to reduce rejects in electronic and electric substances and to establish recycle and reuse systems so as to reduce the possible hazard and compact of such substances to human body and environment in the time of reject, burial and burns.There are 6 kinds of harmful substances in the RoHS Directive.