Preface Recently, a heartbreaking lead poisoning incident occurred in a kindergarten in Tianshui, Gansu. According to the official report, out of 251 children in the kindergarten, 233 had abnormal blood lead levels, with some children’s blood lead content exceeding the normal value by several times. At present, after investigation by public security organs, the cause of this lead poisoning incident is suspected to be the illegal addition of colored paint in the kitchen to make food. The public security department seized the remaining paint from the kindergarten and tested it for lead content, with clear labeling on the packaging indicating non-edible. The working group found that the three-color red date rice cake and corn roll sausage left by the kindergarten contained lead levels of 1052 mg/kg and 1340 mg/kg, respectively. Faced with such a heartbreaking incident, we must not only send the deepest care and encouragement to these affected children and families, but also through popular science knowledge, let
When writing this popular science article, I am also sorting out the measures I should take, which are summarized at the end of the article. As you read, will you also sort out the measures you want to take? Please share with everyone in the comments section.
every parent know how to protect their children from lead exposure and what to do if their blood lead levels increase.
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Global Burden of Disease
Children are more susceptible to lead exposure than adults, because:
They often put toys, supplies, and hands in their mouths to chew, which makes them more likely to come into contact with lead-containing dust and debris. Infants and young children absorb 4-5 times more lead into their bodies than adults, with children absorbing an average of 40%-50% of lead, while adults absorb 10%-15%. Lead is more likely to enter their brains, and the rapidly developing brain is also more sensitive to the neurotoxicity of lead. Lead can cause cognitive ability, IQ, academic performance to be damaged, and increase the incidence of problematic behaviors.
data estimates that the number of children in China with blood lead levels above 50 µg/L is estimated to be 31,237,708.
Which children need blood lead testing?
In our country, 35.1% of children have blood lead levels higher than 50 μg/L. Our country has a vast territory, and the economic and health development levels of various provinces and cities are not balanced, there are significant differences in blood lead levels among children in different provinces.
In Guizhou and Heilongjiang, most children’s blood lead levels are between 50-100 μg/L, and in Yunnan Province, more than 60% of children have blood lead levels higher than 100μg/L. There are also many areas where statistical survey data on children’s blood lead are still missing. In view of the current situation, we suggest:
At present, Distinct Health clinics across the country can perform blood tests, to make an appointment for testing, please click 👉: Book a quick test channel.
How is blood lead tested?
Venous blood lead testing is more accurate. Before blood collection, the blood collection site should be carefully cleaned with an alcohol swab to remove lead from the skin surface. When collecting blood, attention should be paid to using lead-free anticoagulant blood collection tubes. After blood collection, it is necessary to mix well to avoid blood coagulation, which would result in a lower blood lead value than the actual level.
Capillary blood collection (capillary blood collection) is more convenient, and if operated correctly, it can be used as a screening method.If capillary blood lead is elevated (greater than 35 μg/L) a venous blood test must be conducted to confirm.
Distinct Clinic conducted a comparison of venous blood and capillary blood lead levels by the same experimenter, and the difference was 1-5ug/L.
What is a safe level of blood lead?
You may have seen such statements that a blood lead value below 100 μg/L is a normal level, or a blood lead value below 50 μg/L is relatively safe. Which statement is correct?
In 2006, the National Health Commission of China set the standard for children’s high lead blood levels at 100 μg/L. In 2021, several authoritative health medical institutions and universities jointly formulated the “0-6 years old children’s blood lead reference standard” and suggested lowering the standard to 50 μg/L.
However, more and more evidence indicates that common blood lead concentrations even below 50 μg/L may also damage cognitive ability.
In fact, children’s blood lead as long as it is above the detection limit, that is, the test report can give a value, measures should be taken.
What should be done if blood lead results come out?
I saw a child’s report on Xiaohongshu with a blood lead of 70 μg/L. The report did not indicate an abnormality, and the parents thought there was no problem at first.
Someone in the comment area told her that the child’s blood lead level was high and some measures needed to be taken. Some suggested calcium and zinc supplementation, or taking some oral liquids claimed to be able to remove lead, and others suggested removing brightly colored toys from the home.
If a child’s blood lead can detect a value, rather than being below the detection line, some measures need to be taken. However, what the child needs is not to take various lead-removal oral liquids, or zinc and calcium supplementation, but to first analyze the sources of lead exposure in the living environment and take measures to eliminate lead pollution.
Below are the measures that all children need to take to prevent lead poisoning:
(Reference material: 11, click to see the large picture)
Avoid lead pollution sources as much as possible
The United States lowered the reference level of blood lead to 35 μg/L in 2021, but also emphasized that adopting this standard is only because 97.5% of American children’s blood lead levels are below this level, and it is not considered that levels below this do not require measures.
Lead can be added to paint and coatings for moisture-proofing, corrosion protection, and to increase drying ability and durability. Due to cost reduction and other considerations, lead-containing raw materials are still used by many domestic paint manufacturers. For example, in this lead poisoning incident in Tianshui kindergarten, it was the kindergarten’s illegal use of colored paint for food production.
Lead additives are most commonly used in solvent-based coatings, while water-based latex paints rarely intentionally add lead compounds.
The most commonly added lead compounds in solvent-based coatings are lead pigments, such as lead chromate and molybdate, which are bright yellow, orange, and red pigments, and they can also be mixed with other pigments to form bright colors like green and purple.
(Reference material 13)
Children’s playground facilities and other entertainment facilities collected 13 samples, including 9 children’s playground facilities, 1 outdoor basketball hoop, and 3 community fitness equipment, with a non-compliance rate of about 53.8% (7 samples), and the non-compliance rate of children’s playground facility samples is about 44.4% (4 samples). The highest total lead content was found in the “self-control airplane ride” of a children’s playground in Yuelu District, Changsha City, with a total lead content of 644,000 ppm.
Researchers also surveyed solvent-based wood coatings sold on China’s mainstream online platforms, collecting 29 samples, with a non-compliance rate of 37.9% (11/29).
Lead content non-compliant paint samples are distributed in red, yellow, blue, and brown color systems, which coincides with the color range of lead-chrome pigments to a large extent. The non-compliance rate of red color samples is 70.0%.
Among the samples, 18 (62.1%) do not have 3C certification (“China Compulsory Product Certification”), among which 61.1% of the total lead content is non-compliant. 3 samples show 3C logo on the platform’s product introduction page, but actually do not have 3C certification, among which 1 sample’s total lead content is seriously excessive, up to 10,300 ppm.
All 11 samples with 3C certification (only 2 provided 3C certification information on the platform’s purchase page) did not detect lead components. There are situations where false information is difficult to distinguish in the product introduction of online stores, and the platform’s product introduction also does not pay attention to the 3C certification of coatings.
2. Traditional Chinese patent medicines or folk medicines that may contain lead
Lead compounds have a strong bactericidal and insecticidal effect and were once an important “antibiotic” and “deworming medicine” for people in ancient countries to treat infectious diseases.
Lead-containing traditional Chinese medicine began in the “Shennong’s Herbal Classic” and has a long history in clinical application of traditional Chinese medicine. Traditional Chinese medicine believes that lead-containing traditional Chinese medicine has the effects of suppressing counterflow, phlegm, malaria, killing worms, calming, and detoxification, and is commonly used to treat epilepsy, asthma, malaria, skin diseases, intestinal parasites, and various infectious diseases.
Li Shizhen’s “Compendium of Materia Medica” contains lead-containing traditional Chinese medicine, which is still in clinical use today, including lead cinnabar, mitragyna, lead, lead霜, and lead powder. There are also reports of cases of lead poisoning in infants caused by the use of red dan powder to prevent prickly heat.
Not only in China, but also in Thailand, Myanmar, Spain, India, there are some lead-containing herbs.
3. Substandard children’s products
In 2018, researchers from Tsinghua University purchased 100 children’s toys from the three largest e-commerce platforms in China (JD, TB, Tmall) and conducted testing and analysis.
The results showed that the average lead concentration of toys purchased from the TB platform was 219 mg/kg, significantly higher than JD (average lead concentration of 25 mg/kg) and Tmall (average lead concentration of 32 mg/kg).
Of the toys purchased from TB (a total of 33 types), 12% of the total lead content exceeded the “GB 24613-2009 Limit of Harmful Substances in Coatings for Toys” (600 ppm limit), with the highest lead content reaching 1677 ppm.
4. Substandard ceramic tableware
To increase the mechanical strength, surface gloss, and artistic decorative effect of daily ceramics, lead and other heavy metal raw materials and colored glazes may be added.
From the national supervision and inspection work of the State Administration for Market Regulation from 2009 to 2020, the qualification rate of ceramic tableware has been on the rise, and the lead leaching qualification rate in 2020 was 100%.
(Reference 9)
The quality inspection report from the State Administration for Market Regulation points out that the lead leaching from underglaze color products, underglaze color products, colored glaze porcelain, and white porcelain is minimal or almost non-existent, and only a few overglaze color products have lead leaching exceeding the national standard’s maximum allowable limit.
The report suggests the following methods for selecting safe overglaze color products:
5. Secondhand smoke
There are more than 7000 chemical substances in tobacco smoke, including lead..
Research has found that children with high levels of serum cotinine (a metabolite of nicotine, which can assess secondhand smoke exposure) have higher blood lead levels, suggesting that secondhand smoke exposure may be a source of children’s blood lead.
6. Leaded gasoline
At the end of the 1990s, China began to gradually promote unleaded gasoline. A report from 2004 showed that after more than 2 years of implementing unleaded gasoline in Shanghai, the lead concentration in ambient air decreased, thereby reducing the blood lead levels of school-age children.
Through a preliminary cost-benefit analysis, after the implementation of unleaded gasoline measures, the loss of nearly 600 million US dollars (about 5 billion yuan) in Shanghai can be avoided due to the decrease in blood lead levels in school-age children.
7. Parental occupational exposure
If parents’ workplaces involve exposure to lead, they need to wash their hair, take a shower, and change clothes after work before going home, which can reduce lead pollution in the home.
Occupations that may involve lead exposure: police officers, plumbers, pipe fitters, lead miners, lead smelters and refineries, painters, auto mechanics, glass manufacturers, shipyard workers, printers, plastic product factory workers, steel welders or cutters, construction workers, rubber product workers, lead-acid battery manufacturers and recyclers, and those who recycle tin foil ash from cemeteries, etc.
8. Spices in some countries
Spices grown in lead-polluted areas can absorb lead, and lead may also be part of the spice grinding machinery. Sometimes, lead is deliberately added to spices to increase color and weight.
A study found that among about 1496 samples of about 50 spices collected from 41 countries in New York, more than 50% of the samples could detect lead.
The highest lead concentrations were found in spices purchased in Georgia, Bangladesh, Pakistan, Nepal, and Morocco.
9. Turmeric
In Bangladesh and many other South and Southeast Asian countries, turmeric is used as a cooking spice, natural pigment, and medicine for treating digestive system diseases, inflammation, and infections.
Curcumin is widely studied for its anti-inflammatory and antioxidant properties and is sold as a health supplement. However, some producing areas of turmeric have been found to contain lead.
10. Traditional cosmetics in some countries
Traditional kohl or surma eyeliner used in South Asia and Africa has been found to contain high concentrations of lead. The traditional red or orange-red cosmetic powder used by Indian women, Sindoor, may contain lead. What measures should be taken for children with different levels of blood lead results?
The above measures to prevent children’s lead poisoning and avoid lead pollution sources are needed by every family.
Blood lead < 35 μg/L
1. Retest when necessary:
a) If the child is at risk of lead exposure, retest after 6-12 months. Regular monitoring at 1 and 2 years old. b) For babies < 12 months old, retest blood lead after 3 to 6 months, as the risk of lead exposure may increase with the child’s increased mobility. c) If blood lead was tested before the warmer weather. Blood lead tends to increase during warm periods, possibly related to increased lead exposure from dust and soil. Therefore, children with blood lead levels above the detection value 2. Regular child health check-ups, assess nutritional status, physical and mental development, and risk of iron deficiency 3. Understand environmental lead exposure risks and try to avoid risks. Blood lead 35~140 μg/L
1. Take the measures above for blood lead < 35 μg/L.
2. Retest venous blood lead within 1 to 3 months to observe if the blood lead level has increased. If the lead level is stable or decreasing, retest blood lead every 3 months until blood lead < 35 μg/L. Then retest blood lead once a year until the age of 6.
3. Analyze possible lead pollution sources and take preliminary measures to eliminate pollution.
4. Adequate intake of calcium, vitamin C, and iron-rich foods, regular meals, reduce lead absorption, and prevent pica. Usually, there is no need to supplement calcium and vitamin C. There is no need for routine iron treatment without evidence of iron deficiency.
5. Check blood routine, ferritin, C-reactive protein to determine if there is coexisting iron deficiency. If anemia or low ferritin is present, corresponding treatment should be carried out to ensure sufficient iron.
6. Because lead may affect neurodevelopment, standardized developmental screening should be conducted during child health care.
7. The child’s siblings, roommates, playmates, parents/main caregivers may also be at risk of increased blood lead and may also need blood lead testing.
Blood lead 140~449 μg/L
1. Take the measures above for blood lead 35~140 μg/L.
2. Retest blood lead within 1 to 2 weeks, the higher the blood lead, the faster the retest.
3. Refer to a lead poisoning specialist. If based on environmental investigation and medical history, it is suspected that the child has ingested lead-containing objects, perform an abdominal plain film X-ray examination. If lead-containing foreign objects are found on the X-ray film, it is recommended to use whole bowel irrigation.
Blood lead >449 μg/L
1. Take the measures above for blood lead >140 μg/L.
2. Retest blood lead, the time for retesting depends on whether there are symptoms of lead poisoning and blood lead levels.
3. Perform chelation therapy by a lead poisoning specialist. If it is not guaranteed that there is no lead pollution at home, or if blood lead levels >699 μg/L, hospitalize for treatment.
What symptoms may lead poisoning have?
Let’s take a look at what measures should be taken for children with different levels of blood lead results.
(not too low to be undetectable)
in the fall or winter need to be retested in the summer.
1. Lowest level of lead exposure: may have no symptoms, or
Decreased learning and memory Decreased language ability Early signs of hyperactivity or hyperactivity disorder Decreased IQ Impaired speech and hearing functions
2. Low-level lead exposure
Muscle pain or paresthesia Mild fatigue Irritability Somnolence Occasional abdominal discomfort
3. Moderate lead exposure
Arthralgia General fatigue Difficulty concentrating Muscle overfatigue Headache Tremor Diffuse abdominal pain Vomiting Weight loss Constipation
4. High-level lead exposure
Paralysis or paralysis Encephalopathy May suddenly cause epileptic seizures, changes in mental state, coma, and death Lead line on the gums Intermittent, severe abdominal colic
(blue-black)
What measures will I take in the future to protect my child?
First, do not give children folk remedies, many folk remedies may contain lead or mercury, arsenic and other heavy metals, especially some traditional customs in some areas for newborns to use yellow or red powder for skin care, which can cause severe poisoning in children. Pregnant or breastfeeding women should also avoid using folk remedies, black ointments, etc.
1. Check the child’s blood lead
2. Pay attention to hygiene
Pay more attention to washing hands and face, and be sure to wash hands and face after playing and before eating and sleeping.
Pay attention to the cleanliness of the home’s desktops and floors. Clean toys. Use cleaning agents with surfactants for cleaning, and use wet cleaning instead of dry sweeping.
Open the faucet in the morning and let the water run for a minute before using it.
3. Purchase reliable daily necessities
When purchasing toys and stationery, choose big brands, and try not to buy multi-amine colors (passionate red, warm and bright orange, sunny yellow).
Clean up the porcelain tableware at home, discard those with cracks, overglaze color, and overly bright surfaces. If decorating again, I will avoid multi-amine colors, choose big brands, purchase products with 3C certification, and choose water-based latex paint.
4. Be more vigilant against secondhand and thirdhand smoke
If relatives or guests want to smoke at home, I will ask them to smoke in the yard, and will not endure silently because of face.
5. Reduce unnecessary dangerous contacts
If traveling, I will not be curious to buy local herbs, spices, cosmetics. I was planning to take my daughter to play with colored glass parent-child handicrafts, not playing anymore.
What measures will you take? Please share in the comments section!
| References
Use hand sanitizer.
Use cold water for cooking and boiling water, do not use hot water.
