Sources of Lead in the Environment - Case Study Example

Lead Exposure in Children Introduction Lead is a heavy metal which has been useful for human beings for several decades (Marcus, . However,it is a toxic substance and can cause many acute and chronic health problems in both children and adults. One of the important sources of lead in the environment is lead paint, which is the most common source of toxicity in children (Crane, 2009). It virtually affects every organ in the body and contributes to significant morbidity and mortality. Infact, in modern times, lead toxicity is the most important environment-related illness affecting children. It can lead to various organ system problems and affect the learning and behavior of the child (Marcus, 2010). It is because of these attributes, lead poisoning in children has been identified as a major public health challenge by most health related organizations in the world like World Health Organization and Center for Disease Control and many countries have taken appropriate measure to decrease exposure to lead. According to CDC (2000; cited in WHO, 2010), even small blood levels of lead, as much as 10ug/dL can lead to heath problems. In this essay, the consequences of lead toxicity in children will be discussed with reference to suitable literature. Pathophysiology The main reason why lead affects the organ systems is because it affects the functioning of several enzymes. Lead, like any other heavy metal, forms a ligand with sulfhydryl groups and affects proper functioning of the enzymes. One of the significant effects of lead is on the production of heme. The heavy metal interferes during the dehydration phase of aminolevulinic acid, thereby interfering with incorporation of iron into the protoporphyrin molecule and causing decreased production of heme. Heme is very essential for cellular oxidation and thus, any deficiency of heme will ultimately cause problems. Lead also interferes with the metabolism and absorption of calcium and Vitamin D (WHO, 2010). Lead is mainly excreted in bile and urine and the elimination rate of lead depends on the tissue (Marcus, 2010). Demographics Currently, lead toxicity is considered to be the most common chronic environmental illness, especially in children. While adults develop lead toxicity due to occupational exposure, children develop toxicity because of handling of toys made with lead paint and eating chips of lead paint from walls. Children who live in houses which are painted with lead-based paint are at increased risk of lead toxicity. Children less than 3 years of age are likely to put various things into their mouths and thus are at increased risk of ingestion of lead containing substances. Also, the growth of brain in these children is very fast and thus they are more likely to have problems related to development of brain (Marcus, 2010). Clinical presentation There are no pathognomonic symptoms for chronic or acute lead exposure. The diagnosis is mainly based on high index of suspicion. Infact, in many countries, it is mandatory to screen children for lead poisoning regularly. Lead poisoning must be considered in a child who is highly irritable for no appropriate reason or illness, is excessively lethargic or sleepy, has frequent headaches, abdominal pain, poor appetite and constipation and, who has fever of unknown origin (Marcus, 2010). Learning difficulties and recurrent abdominal pain are other features of lead poisoning (WHO, 2010). Lead toxicity must also be considered in those who use herbal medicines for medical remedies and in children who have changes in their activity levels which are vague. Children who have delayed weaning are at increased risk of development of pica and subsequently lead poisoning. Also, those living in houses built before 1978 are likely to be at risk of exposure to lead-based paints. In adults, chronic lead poisoning manifests are sleep disturbances. As far as physical findings are concerned, there are no definite signs. However, some signs like anemia, hyperactivity or lethargy, gout arthritis, peripheral neuropathy and CNS toxicity signs complement the suspicion of lead toxicity (Marcus, 2010). Exposure to lead in fetal stage and childhood can not only lead to various learning difficulties like dyslexia, mental retardation and behavioural problems (WHO, 2010). Causes Occupations which increase the risk of exposure to lead are scrap metal workers, welders, lead workers and glassmakers. Children employed in these factories due to child labor can get exposed to lead. Also, parents working in these factories can carry the dust home and cause lead exposure to their children. Certain hobbies are associated with increased lead exposure and they are soldering, remodeling older homes, making bullets and making fishing weights. Certain daily-use color cosmetics and folk remedies also have salts of lead. Other sources of lead toxicity include dust contaminated with lead in old houses (Newsanchormom, 2007), contaminated soil, water and air. Water is a source when lead pipes are used for water transmission. The amount of lead that dissolves in water depends on the hardness of the water, the standing time, temperature and also the pH. Motor exhaust also contains lead from leaded gasoline (WHO, 2010). Clinical response to lead exposure is thought to be modulated by age, genetics and activity of the individual. When fragments of bullets are not removed immediately, the risk of lead toxicity is increased. When lead based foreign objects are ingested by children, lead content in the substances easily dissolves in the acid of the stomach and gets absorbed. There is some evidence to show that malnutrition increases the risk of lead toxicity. Absorption is lead is increased when the diet is rich in fats or is poor in calcium, Vitamin C, fiber and iron (Marcus, 2010). Laboratory diagnosis Whenever, there is high index of suspicion of lead toxicity, it must be confirmed with a simple criterion test, the blood lead level or BLL. BLL above 10ug/dL is significant. Individuals with levels between 10 and 20ug/dL need frequent testing and follow up. The source of lead exposure must be identified and removed. Complete blood picture in lead poisoning reveals microcytic hypochromic anemia. This anemia can be because of enzyme inhibition or can be due to decreased erythropoietin production and decreased production of red cells. Lead poisoning can also cause acute hemolytic anemias because of increased fragility of red blood cells. Children and adults diagnosed with lead toxicity must be tested for liver profile, renal profile and uric acid levels. Subtle nephrogenic changes may be observable in lead poisoning and it must be identified and treated, because it can contribute to treatment failures. Other tests include abdominal X-ray to look for radio-opaque bodies in the gastrointestinal tract, X-rays of long bones with lead lines and spinal tap analysis, in case the individual has altered mental status (Marcus, 2010). Treatment The first and foremost aspect of treatment of lead poisoning is to remove the child from the source of exposure. Chelation is the extreme treatment for lead toxicity which is given only when, despite separation, there is no improvement in the level of lead, or when the lead level is beyond 60ug/dL which is encephalopathogenic. In case of acute toxicity, the child may develop seizures or develop coma, in which case airway management and establishing proper circulation becomes utmost important (Marcus, 2010). A patient who is severely symptomatic because of lead poisoning must be managed in a hospital setting. An intravenous drip must be initiated with normal saline. In case of acute oral ingestion, gastric lavage and irrigation of the bowel with polyethylene glycol must be done (Marcus, 2010). Chelation therapy must be initiated with caution. The drugs used for this purpose is Edetate calcium disodium or EDTA, dimercaprol, also known as British antilewsite or BAL, dimerval, D-penicillamine and succimer or DMSA. Any patient on chelation therapy must be monitored for hepatic and renal functions and fluid and electrolyte levels (Marcus, 2010). Complications The worst complication of lead poisoning is encephalopathy. Other complications include renal, cardiac, hepatic and neurological problems, raised intracranial pressure, syndrome of inappropriate excretion of antidiuretic hormone, hypertension and chelation related renal impairment (Marcus, 2010). Prognosis The prognosis of asymptomatic lead poisoning is much better than symptomatic poisoning. Lead encephalopathy can be fatal. Children can develop hyperactivity, learning disabilities, dyslexia and depressed functions in school. In adults, sexual impotence, decreased sexual performance, increased fetal wastage and infertility can occur (Marcus, 2010). Preventive measures Government has a major role to play in the prevention of lead poisoning. Many countries in the world have recognized lead toxicity as a major public health issue and have banned the use of leaded gasoline, lead paints for indoors, and lead pipes for drinking water. In Germany, any paint that contains lead levels of "≥ 1.0 milligram per cm², or 0.5% by weight or 5,000 ppm by weight" (German Protocols, 2009). According to German Protocols (2009), "any lead-based paint on a friction surface that is subject to abrasion and where the lead dust levels on the nearest horizontal surface underneath the friction surface (e.g., the window sill, or floor) are equal to or greater than the dust-lead hazard levels, any damaged or otherwise deteriorated lead-based paint on an impact surface that is caused by impact from a related building component (such as a doorknob that knocks into a wall or a door that knocks against its doorframe), any chewable lead-based painted surface on which there is evidence of teeth marks and any other deteriorated lead-based paint in any residential building or child-occupied facility or on the exterior of any lead hazards as residential building or child-occupied facility" are paint-lead hazards. The protocols define dust-lead hazard as "surface dust in a residential dwelling or child-occupied facility that contains a mass-per-area concentration of lead ≥ 40 µg/ft² on floors or 250 µg/ft² on interior window sills based on wipe samples." Soil-lead hazard includes "bare soil on residential real property or on the property of a child-occupied facility that contains total lead ≥ 400 ppm (µg/g) in a play area, or an average of 1,200 ppm of bare soil in the rest of the yard based on soil samples" (German Protocols, 2009). In places where lead pipes cannot be replaced, cold water must be flushed before using water. Proper water treatment must be provided before drinking like filtering. According to the WHO (1993; cited in WHO, 2010), "the health based guideline for lead in drinking water is 0.1 milligrams per litre." At places of work where the risk of exposure to lead is high and unavoidable, employers must stress the use of protective gadgets. It is important to have a surveillance programme to ascertain lead toxicity in vulnerable groups like pregnant women, young children and in occupations. Children with abnormal levels of lead must be referred to proper medical care. Conclusion Lead poisoning is the most important environmental toxicity in children and adults. Children are vulnerable to lead toxicity because of their indulgence in putting various substances like toys, wall chips, etc. Lead toxicity can also occur in children whose parents work in lead dust factories, who consume water from lead pipes and who live in areas polluted with motor exhaust. Lead toxicity leads to several health related problems, the most significant of which are anemia, learning disabilities, behavioural problems, recurrent head ache and abdominal pain, lethargy and hyperactivity. Acute toxicity can result in encephalopathy and seizures. Exposure in fetal stage or early childhood can result in mental retardation, learning deficits and behavioural defects. Currently many health organizations and countries have adapted laws to decrease lead toxicity. The most significant law has been the ban of lead based paints in toys and in houses. References Crane, L. (2009). Video: Lead poisoning in children. on 4th December, 2010 from http://www2.alabamas13.com/news/2009/nov/12/lead_poisoning_in_children-ar-409834/ German Protocols. (2009). Lead-based Paint. Retrieved on 4th December, 2010 from http://www.schweinfurt.army.mil/directorates/dpw/documents/17_FGS_Lead-Based_Paint_Management.pdf Marcus, S. (2010). Toxicity, Lead. Emedicine from WebMD. on 4th December, 2010 from http://emedicine.medscape.com/article/815399-overview Newsanchormom. (2007). Lead Poisoning. Youtube. on 4th December, 2010 from http://www.youtube.com/watch?v=zpeL5Qtb_oUnewsanchormom WHO. (2010). Lead poisoning. on 4th December, 2010 from http://www.who.int/water_sanitation_health/diseases/lead/en/ Read More