In determining a relationship between household dust lead and BLLs, we log-transformed both variables and applied Pearson correlation analysis. To examine changes in BLLs 1 year after closure of the lead enterprises, we used paired t tests to compare the baseline and follow-up BLLs among retested children. We also used a multivariate linear model to compare changes in BLLs with exposure levels, with adjustment for potential confounding factors.
All data analyses were carried out with the SPSS version The geometric mean for soil lead in the low-exposure village was All were higher than in the control village The soil lead level in medium- and high-exposure villages far exceeded the maximum level of milligrams per kilogram considered safe under Chinese regulations.
The geometric mean for household dust lead in the low-exposure village was Table 1 summarizes sociodemographic data and potential risk factors of children by exposure level. The average age of children in the sample was 7 to 8 years, with slightly more boys than girls. Parental education level was lower in the control group.
More than half of parents in the polluted area admitted bringing their work suits or tools home, but very few families used lead pottery at home. Daily milk consumption was more common and bathing was more frequent among children in the polluted area than it was among those in the control area. We identified 29 houses in the polluted area but none in the control village that were storing lead ore. Fujian Province, China, Table 2 presents children's BLLs.
The mean value for children in the polluted area was We found BLLs of 10 micrograms per deciliter or higher in Among children in the polluted area, average BLLs increased with exposure level, suggesting an exposure—response gradient. The local health department sent 25 children with BLLs greater than 25 micrograms per deciliter to the hospital. These children received supportive and chelation therapy.
We searched for possible determinants of BLL through linear regression analysis Table 3. All 3 exposure levels were significantly associated with elevated BLLs compared with the control group. We detected a gradient of BLLs with exposure level: Other significant risk factors were male gender, longer residence in the polluted area, parental lead-related occupations, and parents often bringing work suits or tools home.
Milk consumption and higher parental education were inversely associated with BLL. We used years of residence in the polluted area in the final model. We adjusted for use of lead pottery, house near main road, and lead ore stored in house. Figure 2 is a scatter plot of household dust lead log against BLLs log in 84 children whose household dust was sampled.
A significant correlation remained even after excluding the control group. Scatter plot with fit line between log-household dust lead against log-BLL among 84 children: Children's BLLs rose with increasing household dust lead, with a coefficient of 0. Table 4 shows the changes in BLLs 1 year after the intervention. Among the entire group, the mean BLL decreased from The reduction tended to be greater among children in lower-exposure villages. In a further multiple linear regression, in which the difference between baseline and follow-up BLLs was the outcome variable, we found smaller reductions among children with medium 1.
We examined environmental lead pollution resulting from industrial sources and its impact on the BLLs of children in a rural area of China. The lead concentrations in soils were well above the already lax national standards. We did not report lead concentrations in the air because air samples were taken after the closure of lead industries and did not reflect environmental exposure levels.
The poorly regulated activities of mining, separating, transportation, and smelting of lead were responsible for the serious lead pollution in the area. After ruling out other potential exposure sources, we found that lead exposure levels resulting from industrial pollution were strongly associated with elevated BLLs in children. Our results revealed a huge impact of environmental lead pollution on children's health. Environmental quality in Chinese rural areas was generally thought to be much better than in industrial urban cities, before the era of booming township—village enterprises.
Most of these alliances lacked the technology and facilities to treat hazardous industrial wastes. Although concrete data on the resultant health effects are scant, no doubt remains that the township—village enterprises are major sources of environmental pollutants in rural areas, and our study provides supportive evidence for this concern.
Previous studies on children's BLLs in China 8 — 11 , 16 — 20 focused mostly on urban areas. Among the limited studies conducted in rural areas, 1 revealed that a small battery-recycling plant caused serious environmental lead pollution and severe adverse affects on children's BLLs.
We were able to measure lead in soil and household dust, thus documenting serious environmental pollution. We observed a clear gradient of BLLs in children with increasing exposure levels.
Lead Pollution Effects: Its Sources & Control
We found a moderate correlation between household dust lead levels and BLLs in a subgroup of children whose house dust was sampled. All results pointed toward a strong relationship between environmental lead pollution and BLLs in children, and the association was independent of other potential sources of exposure and confounding factors. The children could be exposed to lead from several major routes. Polluted air was a source, especially fumes from lead smelting, whose molecules are small enough to be absorbed through the bronchiole tree. Lead deposited in soil and dust could also be ingested by children directly or through the food chain.
Lead may exist in the environment in different chemical forms. A recent study analyzed the associations of exposure to different forms of lead with BLLs in Chinese children and found that carbonate lead and humic acid lead were significantly related to elevated BLLs. Parental occupations related to lead might result in indirect exposure. We found these 2 variables to be significant risk factors for elevated BLLs, in agreement with a previous study.
These children had a higher average BLL than did others in their village Other sources of lead exposure might be lead-based paint, lead pesticides, or lead-containing toys and tableware, but not leaded gasoline, which was banned by China in This high background risk is typical for vast rural areas of the country.
A recent article reviewed 49 studies mostly published in Chinese journals on BLLs in rural children from to and found levels ranging from 4. A notable finding in our follow-up to the remediation intervention was that BLLs significantly decreased among children at all exposure levels, although the average value was still higher than 10 micrograms per deciliter.
Similar BLL reductions have been observed in children throughout the United States 28 and in New York State 29 and have been attributed to public awareness, lead paint remediation, replacement of older homes, and phasing out of lead-containing gasoline. On the other hand, lead in soil and other parts of the environment does not dissipate quickly, and these lead sources may exert lasting adverse effects on children. To the best of our knowledge, ours is one of the very few studies reporting a positive association between environmental lead pollution and children's BLLs in a rural area of China.
The association was unlikely to be a chance finding because of the adequate sample size and consistent results. Environmental sources of lead and the outcome of BLL were objective parameters and were determined by standard laboratory protocols carried out independently of one another. In addition, we followed children with high BLLs to determine the change in their levels after 1 year, as a possible indicator for the effect of closure of the lead industries. We measured environmental lead levels by collecting samples at a village level only once, which might not have reflected the actual exposure of individual children.
The lack of individual exposure data prevented us from documenting a more precise exposure—response relationship, although we observed a clear increasing trend of the children's BLLs with increasing environmental lead levels. We sampled household dust from only 60 families, largely because of limited resources. However, the lead levels in household dust were consistent with the soil lead levels in different exposed villages, indicating the samples were representative to a great extent. We retested BLLs only in children with high initial levels, so we do not know what happened to the BLLs of the other children after 1 year.
Furthermore, we did not remeasure environmental lead after 1 year, so we could not assess the degree of persistence of lead contamination in the environment and link it to the retested BLLs. Recall bias and interviewer bias were unlikely, because the BLLs of the children were not known at the time of the interviews.
Inaccuracies could have occurred during collection of information on other possible exposures or confounding factors and resulted in misclassifications, but such misclassifications were unlikely differential and thus did not significantly distort the association between environmental lead pollution and children's BLLs. We assessed environmental lead pollution caused by rural industries and its impact on BLLs among children living nearby. We measured average BLLs as high as Our results could be a wake-up call for the revamping of governmental policies that supported rural industries without tightly regulating their hazardous discharges and environmental pollution.
Efficient strategies and public health policies are urgently needed to control and prevent environmental lead pollution in both rural and urban areas. The environmental lead pollution we report represents just the tip of an iceberg, and more studies are needed to evaluate environmental pollution from other harmful chemicals and its health effects on children in cities and in the vast rural areas of China. BLLs in children at high risk should be screened and monitored regularly.
Children with high BLLs should receive medical attention and appropriate treatments, with financial support from the responsible industries. In addition, extensive education programs should be launched to enhance public awareness of lead exposure and its adverse health effects throughout the country.
This study was approved by the Centre for Prevention and Control of Occupational Diseases and Chemical Poisoning, and the Fujian institutional review board. Oral informed consent was obtained from all study participants and their parents. National Center for Biotechnology Information , U. Am J Public Health.
Lead Pollution Effects: Its Sources & Control
Author information Article notes Copyright and License information Disclaimer. Reprints can be ordered at http: Accepted July 26, This article has been cited by other articles in PMC. METHODS We studied a polluted region, estimated to contain more than 20 million tons of natural lead and zinc ore deposits, in a rural mountainous area in the center of Fujian Province. Open in a separate window. Study Population and Blood Testing According to official registry data, children aged 2 months to 14 years were living in the 7 villages.
Environmental Lead Pollution Assessment Lead in soil. Lead in household dust. Questionnaires and Interventions We provided a structured questionnaire to be used by trained investigators to interview the children's parents and collect information on children's exposures to lead, including location, environment surrounding the house, condition of the house, and length of residence. Statistical Analysis The data analysis centered on the association between environmental lead pollution and children's BLLs.
Limitations We measured environmental lead levels by collecting samples at a village level only once, which might not have reflected the actual exposure of individual children. Conclusions We assessed environmental lead pollution caused by rural industries and its impact on BLLs among children living nearby. Bull World Health Organ. Blood lead concentration, blood pressure, and renal function. Lead exposures in U. International environmental health for the pediatrician: Childhood lead poisoning in China. Wang S, Zhang J. Blood lead levels in children, China. However, the biggest impediment to using the vast majority of alternatives relates to current laws in the United States pertaining to armor-piercing rounds.
Laws and regulations relating to armor-piercing ammunition expressly prohibit the use of brass, bronze, steel, tungsten, and nearly every metallic alternative in any bullet that can be shot by a handgun, which at this time is nearly every caliber smaller than 50BMG including the popular.
Navigation menu
Some lead-based bullets are resistant to fragmentation, offering hunters the ability to clean game animals with negligible risk of including lead fragments in prepared meat. Other bullets are prone to fragmentation and exacerbate the risk of lead ingestion from prepared meat. In practice, use of a non-fragmenting bullet and proper cleaning of the game animal's wound can eliminate the risk of lead ingestion from eating game; [] however, isolating such practice to experimentally determine its association with blood lead levels in study is difficult.
Bismuth is an element used as a lead-replacement for shotgun pellets used in waterfowl hunting although shotshells made from bismuth are nearly ten times the cost of lead. Exposure occurs through inhalation , ingestion or occasionally skin contact. Lead may be taken in through direct contact with mouth, nose, and eyes mucous membranes , and through breaks in the skin. Tetraethyllead , which was a gasoline additive and is still used in fuels such as aviation fuel, passes through the skin; however inorganic lead found in paint, food, and most lead-containing consumer products is only minimally absorbed through the skin.
The main body compartments that store lead are the blood, soft tissues, and bone; the half-life of lead in these tissues is measured in weeks for blood, months for soft tissues, and years for bone. Lead has no known physiologically relevant role in the body, [42] [78] and its harmful effects are myriad. Lead and other heavy metals create reactive radicals which damage cell structures including DNA and cell membranes.
The primary cause of lead's toxicity is its interference with a variety of enzymes because it binds to sulfhydryl groups found on many enzymes. Among the essential metals with which lead interacts are calcium, iron, and zinc. One of the main causes for the pathology of lead is that it interferes with the activity of an essential enzyme called delta-aminolevulinic acid dehydratase , or ALAD see image of the enzyme structure , which is important in the biosynthesis of heme , the cofactor found in hemoglobin.
The brain is the organ most sensitive to lead exposure. Diagnosis includes determining the clinical signs and the medical history, with inquiry into possible routes of exposure. The main tool in diagnosing and assessing the severity of lead poisoning is laboratory analysis of the blood lead level BLL. Blood film examination may reveal basophilic stippling of red blood cells dots in red blood cells visible through a microscope , as well as the changes normally associated with iron-deficiency anemia microcytosis and hypochromasia.
Exposure to lead also can be evaluated by measuring erythrocyte protoporphyrin EP in blood samples. Blood lead levels are an indicator mainly of recent or current lead exposure, not of total body burden. Fecal lead content that is measured over the course of a few days may also be an accurate way to estimate the overall amount of childhood lead intake.
This form of measurement may serve as a useful way to see the extent of oral lead exposure from all the diet and environmental sources of lead. Lead poisoning shares symptoms with other conditions and may be easily missed. In most cases, lead poisoning is preventable [80] by avoiding exposure to lead. Recommended steps by individuals to reduce the blood lead levels of children include increasing their frequency of hand washing and their intake of calcium and iron, discouraging them from putting their hands to their mouths, vacuuming frequently, and eliminating the presence of lead-containing objects such as blinds and jewellery in the house.
Since most of the lead in household water usually comes from plumbing in the house and not from the local water supply, using cold water can avoid lead exposure. Screening is an important method in preventive medicine strategies. Prevention measures also exist on national and municipal levels. Recommendations by health professionals for lowering childhood exposures include banning the use of lead where it is not essential and strengthening regulations that limit the amount of lead in soil, water, air, household dust, and products.
In some places, remediation programs exist to reduce the presence of lead when it is found to be high, for example in drinking water. The mainstays of treatment are removal from the source of lead and, for people who have significantly high blood lead levels or who have symptoms of poisoning, chelation therapy.
Lead poisoning
A chelating agent is a molecule with at least two negatively charged groups that allow it to form complexes with metal ions with multiple positive charges, such as lead. People receiving dimercaprol need to be assessed for peanut allergies since the commercial formulation contains peanut oil. Calcium EDTA is also effective if administered four hours after the administration of dimercaprol. Succimer DMSA is the preferred agent in mild to moderate lead poisoning cases. The most reported adverse side effect for succimer is gastrointestinal disturbances. This may be because of the inability of these agents to remove sufficient amounts of lead from tissue or inability to reverse preexisting damage.
Chelation challenge, also known as provocation testing, is used to indicate an elevated and mobilizable body burden of heavy metals including lead. Since lead has been used widely for centuries, the effects of exposure are worldwide. Although regulation reducing lead in products has greatly reduced exposure in the developed world since the s, lead is still allowed in products in many developing countries.
In developed countries, people with low levels of education living in poorer areas are most at risk for elevated lead. Risk factors for elevated lead exposure include alcohol consumption and smoking possibly because of contamination of tobacco leaves with lead-containing pesticides. In adults, blood lead levels steadily increase with increasing age.
Lead Air Pollution
Cases of mass lead poisoning can occur. The government has suspended production at 32 of 35 lead plants. The Zamfara State lead poisoning epidemic occurred in Nigeria in As of October 5, at least children have died from the effects of lead poisoning. Outcome is related to the extent and duration of lead exposure. Exposure to lead may also decrease lifespan and have health effects in the long term.
Lead poisoning was among the first known and most widely studied work and environmental hazards. In the 2nd century BC the Greek botanist Nicander described the colic and paralysis seen in lead-poisoned people. Lead was used extensively in Roman aqueducts from about BC to AD [94] Julius Caesar 's engineer, Vitruvius , reported, "water is much more wholesome from earthenware pipes than from lead pipes.
For it seems to be made injurious by lead, because white lead is produced by it, and this is said to be harmful to the human body. Sugar of lead lead II acetate was used to sweeten wine, and the gout that resulted from this was known as "saturnine" gout. The great disadvantage of lead has always been that it is poisonous. This was fully recognised by the ancients, and Vitruvius specifically warns against its use.
Because it was nevertheless used in profusion for carrying drinking water, the conclusion has often been drawn that the Romans must therefore have suffered from lead poisoning; sometimes conclusions are carried even further and it is inferred that this caused infertility and other unwelcome conditions, and that lead plumbing was largely responsible for the decline and fall of Rome.
Two things make this otherwise attractive hypothesis impossible. First, the calcium carbonate deposit that formed so thickly inside the aqueduct channels also formed inside the pipes, effectively insulating the water from the lead, so that the two never touched. Second, because the Romans had so few taps and the water was constantly running, it was never inside the pipes for more than a few minutes, and certainly not long enough to become contaminated.
However, recent research supports the idea that the lead found in the water came from the supply pipes, rather than another source of contamination. It was not unknown for locals to punch holes in the pipes to draw water off, increasing the number of people exposed to the lead. Thirty years ago, Jerome Nriagu argued in a milestone paper that Roman civilization collapsed as a result of lead poisoning.
Clair Patterson , the scientist who convinced governments to ban lead from gasoline, enthusiastically endorsed this idea, which nevertheless triggered a volley of publications aimed at refuting it. Romans also consumed lead through the consumption of defrutum, carenum, and sapa , musts made by boiling down fruit in lead cookware. Defrutum and its relatives were used in ancient Roman cuisine and cosmetics, including as a food preservative.
There is also no indication how often sapa was added or in what quantity. The consumption of sapa as having a role in the fall of the Roman Empire was used in a theory proposed by geochemist Jerome Nriagu [] to state that "lead poisoning contributed to the decline of the Roman Empire". In , John Scarborough, a pharmacologist and classicist, criticized the conclusions drawn by Nriagu's book as "so full of false evidence, miscitations, typographical errors, and a blatant flippancy regarding primary sources that the reader cannot trust the basic arguments.
After antiquity , mention of lead poisoning was absent from medical literature until the end of the Middle Ages. The painter Caravaggio might have died of lead poisoning. Bones with high lead levels were recently found in a grave thought likely to be his. Caravaggio is known to have exhibited violent behavior, a symptom commonly associated with lead poisoning.
In 17th-century Germany, the physician Eberhard Gockel discovered lead-contaminated wine to be the cause of an epidemic of colic. In the 18th century lead poisoning was fairly frequent on account of the widespread drinking of rum , which was made in stills with a lead component the "worm". It was a significant cause of mortality amongst slaves and sailors in the colonial West Indies.
With the Industrial Revolution in the 19th century, lead poisoning became common in the work setting. The 20th century saw an increase in worldwide lead exposure levels due to the increased widespread use of the metal. The levels found today in most people are orders of magnitude greater than those of pre-industrial society. In the late s through the s Herbert Needleman and Clair Cameron Patterson did research trying to prove lead's toxicity to humans.
ConAgra Grocery Products Company et al. The Plaintiff shall recover its costs on appeal. Studies have found a weak link between lead from leaded gasoline and crime rates. Humans are not alone in suffering from lead's effects; plants and animals are also affected by lead toxicity to varying degrees depending on species. Farm animals such as cows and horses [] as well as pet animals are also susceptible to the effects of lead toxicity.
Lead, one of the leading causes of toxicity in waterfowl, has been known to cause die-offs of wild bird populations. The critically endangered California condor has also been affected by lead poisoning. As scavengers , condors eat carcasses of game that have been shot but not retrieved, and with them the fragments from lead bullets; this increases their lead levels.
From Wikipedia, the free encyclopedia. Lead poisoning Synonyms Plumbism, colica pictorum, saturnism, Devon colic , painter's colic An X ray demonstrating the characteristic finding of lead poisoning in humans—dense metaphyseal lines. Specialty Toxicology Symptoms Intellectual disability , abdominal pain, constipation , headaches, irritability, memory problems, inability to have children , tingling in the hands and feet [1] [2] Complications Anemia , seizures , coma [1] [2] Causes Exposure to lead via contaminated air, water, dust, food, consumer products [2] Risk factors Being a child [2] Diagnostic method Blood lead level [2] Differential diagnosis Iron deficiency anemia , malabsorption , anxiety disorder , polyneuropathy [3] Prevention Removing lead from the home, improved monitoring in the workplace, laws that ban lead in products [2] [4] [5] [6] Treatment Chelation therapy [4] Medication Dimercaprol , edetate calcium disodium , succimer [7] Deaths , [2] Lead poisoning is a type of metal poisoning caused by lead in the body.
Archived from the original on 18 October Retrieved 14 October Annual Review of Medicine. American Journal of Health-System Pharmacy. Archived from the original on 4 May Retrieved 18 May Archived from the original on Archived from the original on 9 October Pediatric Clinics of North America.
Advantages, Limitations, and Future Needs". Principles of Biochemical Toxicology 4th ed. Exposure, evaluation, and treatment". Andrews' Diseases of the Skin: A single group non-randomized clinical trial". Indian Journal of Dermatology. Archived from the original on 14 July Advances in Pediatrics, E-Book. Baran and Dawber's Diseases of the Nails and their Management. Toxicology and Applied Pharmacology. An International Pooled Analysis". Who Is at Risk of Lead Exposure?
Environmental Health and Medicine Education. Department of Health and Human Services. Archived from the original on February 4, The Journal of Rheumatology. Effect Modification by Chronic Lead Exposure". Part 1 of a two-part article details how exposure happens, whom it affects, and the harm it can do".
The American Journal of Nursing. Part A, Clinical and Molecular Teratology. International Journal of Hygiene and Environmental Health. Current Opinion in Pediatrics. An year follow-up report". The New England Journal of Medicine. International Journal of Environmental Health Research. Archived from the original PDF on Archived from the original on September 20, Retrieved September 24, Lead contamination in Uruguay: Reviews of Environmental Contamination and Toxicology. Canadian Medical Association Journal. A Short, Sad History". Archived from the original on March 21, Archived from the original on January 24, Explicit use of et al.
Archived from the original on June 27, Inorganic Lead Exposure and Intoxications. Archived from the original on May 3, Retrieved September 18, Archived from the original on September 12, Archived from the original on 23 January Archived from the original on August 25, Retrieved September 26, Acta Radiologica Stockholm, Sweden: Morbidity and Mortality Weekly Report. Potential for Human Dietary Exposure". Archived from the original on 14 January Archived from the original on 21 May New Delhi , India. Archived from the original on 25 May Retrieved 20 May The Times of India.
Archived from the original on 16 October Retrieved 3 June Retrieved June 4, The two-minute death of a India's favourite noodle brand". Archived from the original on 4 June Archived PDF from the original on Wisconsin department of natural resources. Archived PDF from the original on 28 July Retrieved 10 December Retrieved 9 February Association between blood lead levels and wild game consumption".
Assessment of human health risk from consumption of wild game meat with possible lead contamination among the residents of the State of North Dakota" PDF. Archived from the original PDF on May 26, Retrieved March 2, US Center for Disease Control. The Indian Journal of Medical Research. A Computational Modeling Experiment". Angewandte Chemie International Edition.
Journal of Biological Chemistry. Archived from the original on 5 November Where Does It Lead? Archived from the original on 3 April