WHAT IS LEAD ?
OCCURRENCE OF LEAD IN NATURE
Lead is found in nature, but rarely in pure form but in ores with other metals, meaning you can not find lead on it is own it is always found attached to other metals. — the most abundant one in the Earth's crust being galena (PbS). Natural formation of lead occurs by radioactive decay of uranium and thorium through radon (222Rn).
About 200 sites for solid lead are known worldwide as of 2017, some of this sites are in Argentina, Ethiopia, Australia, Belgium, Brazil, the People's Republic of China, Germany, Finland, France, Georgia, Greece, Greenland, Italy, Canada, Kazakhstan, Kyrgyzstan, Mexico, Mongolia, Namibia, Norway, Austria, Poland, Russia, Sweden, Slovenia, the Czech Republic, Ukraine, the US Virgin Islands, the United Kingdom and the United States of America (USA).
The largest deposits of lead (Pb) in the world are found in the People's Republic of China, the USA, Australia, Russia and Canada.
USES OF LEAD
it is used as a protective shielding around nuclear reactors, particle accelerators, X-ray equipment, and containers used for transporting and storing radioactive materials, manufacture of storage batteries, ammunition (shot and bullets),used to dampen noise and vibration, paint, ceramics, pipes and plumbing materials, solders, leaded gasoline and cosmetics.
TOXICITY OF LEAD
According to World Health Organization (WHO) Lead exposure can have serious consequences for the health of children. At high levels of exposure lead attacks the brain and central nervous system, causing coma, convulsions and even death. Children who survive severe lead poisoning may be left with intellectual disability and behavioural disorders. At lower levels of exposure that cause no obvious symptoms, lead is now known to produce a spectrum of injury across multiple body systems. In particular, lead can affect children’s brain development, resulting in reduced intelligence quotient (IQ), behavioural changes such as reduced attention span and increased antisocial behaviour, and reduced educational attainment. Lead exposure also causes anaemia, hypertension, renal impairment, immunotoxicity and toxicity to the reproductive organs. The neurological and behavioural effects of lead are believed to be irreversible.
Nearly half of the 2 million lives lost to known chemicals exposure in 2019 were due to lead exposure. Lead exposure is estimated to accounts for 21.7 million years lost to disability and death (disability-adjusted life years, or DALYs) worldwide due to long-term effects on health, with 30% of the global burden of idiopathic intellectual disability, 4.6% of the global burden of cardiovascular disease and 3% of the global burden of chronic kidney diseases(The World Health Organization’s 2021 update of the Public health impact of chemicals: knowns and unknowns ).
VULNERABLE GROUPS
The most vulnerable groups to lead poisoning are particularly children and pregnant women due to the weakness of their immune system, and children particularly are not concious of what they put into their mouths.
HOW DO ONE GET EXPOSED TO LEAD POISONING?
People can become exposed to lead through occupational and environmental sources which may results from;
1.inhalation of lead particles generated by burning materials containing lead, for example during smelting, recycling, stripping leaded paint and using leaded aviation fuel; and
2.ingestion of lead-contaminated dust, water (from leaded pipes) and food (from lead-glazed or lead-soldered containers).
HOW LEAD SPREAD IN THE BODY
Once lead enters the body, it is distributed to organs such as the brain, kidneys, liver and bones. The body stores lead in the teeth and bones, where it accumulates over time. Lead stored in bone may be released into the blood during pregnancy, thus exposing the fetus. Undernourished children are more susceptible to lead because their bodies absorb more lead if other nutrients, such as calcium or iron, are lacking. Children at highest risk are the very young (including the developing fetus) and the economically disadvantaged.
CAN WE PREVENT LEAD POISONING?
Lead poisoning can be prevented, but the best way to prevent it is to reduce or entirely eliminate the exposure of lead, WHO through her effort to protect the health of workers, children and women of reproductive age has developed guidelines on clinical management of lead exposure and is preparing guidelines on prevention of lead exposure.
Comments
Post a Comment
Leave a comment please