Childhood lead poisoning from domestic products in China: A case study with implications for practice, education and policy

Abstract

Objective:

This study aimed to report three representative childhood lead poisoning cases in China from domestic products exposure and to highlight their critical implications for practice, education, and policy in prevention and treatment of childhood lead poisoning by health care providers, especially public health nurses.

Design and Sample:

Three representative childhood lead poisoning cases occurring in 2017 were collected and analyzed.

Results:

The lead exposure sources of three cases were evaluated by experts in the field and determined to be tin pots, home factories for tinfoil, and contamination of folk medicine, respectively. These cases demonstrated that the lack of lead exposure risk assessment, insufficient knowledge of potential lead exposure sources, underdeveloped policy and regulations were areas for improvement.

Conclusions:

The best strategies for preventing lead poisoning include an appropriate risk assessment of lead exposure, implementation of comprehensive parental health education, conduction of further research by public health providers, and the application of policy strategies by the government. It was determined that public health nurses are at the frontline of prevention of lead poisoning in children.

1. Introduction

Lead poisoning is one of the most common and best understood childhood diseases caused by an environmental toxin (WHO, 2010). High-level lead poisoning can cause anemia, multi-organ damage, seizures, coma, and even death in children, while chronic low-level lead poisoning can have detrimental effects on cognitive, psychological and neurobehavioral development, and physical health outcomes including sleep disturbance (Liu, Li, Wang, Yan, & Liu, 2013; Liu et al., 2015; Liu et al., 2014; Nussbaumer-Streit et al., 2016). As lead was phased out from gasoline in most countries of the world, many countries have witnessed a large reduction in blood lead levels (BLLs) over the past few decades (Jones et al., 2009; Li, Cao, Gao, Shen, & Yan, 2015; Meyer, Brown & Falk, 2008). In 2012, the U.S. Center for Disease Control and Prevention (CDC) replaced the BLL≥10 μg/dl with BLL of 5 μg/dl in children ages 1–5 years old to identify elevated BLLs (CDC, 2012). However, recent research has informed a consensus that there is no tolerable BLL or threshold below which lead exposure causes no cognitive deficits (WHO, 2010; Wilhelm, Heinzow, Angerer, & Schulz, 2010). In China, elevated BLL is currently defined by a BLL ≥10 μg/dl. Although this standard has not changed, the rate of children with elevated BLL ≥10 μg/dl has declined, yet remains higher than those in the US and European countries (Li et al., 2014), indicating that efforts are still warranted to identify and reduce the potential sources of child lead exposure (Yan, Xu & Shen, 2013). Patterns and sources of exposure to lead may vary greatly between and within countries (WHO, 2010). For example, since the prohibition of leaded gasoline, lead-based paint is considered the main lead exposure source for children in the US (MMWR, 2005). In China, however, according to a survey conducted among 515 children with BLLs ≥5 μg/dl at a lead poisoning clinic, the majority of non-industrial exposure sources were lead-contaminated folk medicine, tin pots, and tinfoil with only one participant indicating lead exposure from lead-based paint (Ying et al., 2018). Non-industrial lead exposure sources are commonly culture-related, region-specific and present in the home environment, making it difficult for the health care providers to identify, diagnose, treat, and educate. The aim of this study was to assess the implications of these case studies on practice, education, and policy in prevention and treatment of childhood lead poisoning based on three cases from domestic products, with attention paid to the potential role of public health nurses.

2. Case studies

The three following cases were collected between 2016 and 2017 by a pediatric lead poisoning treatment clinic in a hospital in Shanghai, China. This facility is the main referral center for childhood lead poisoning treatment in China and has been established for more than 20 years. The patients all presented nonspecific symptoms, such as attention problems, hyperactivity, irritability, and shortness of temper. They were initially seen by physicians at their local hospitals where their BLL’s were tested, but they were not treated effectively. According to the guidelines issued by Ministry of Health of the People’s Republic of China, the diagnosis criteria of BLL for elevated BLL, mild lead poisoning, moderate lead poisoning and severe lead poisoning among children are 10–19.9 μg/dl, 20–24.9 μg/dl, 25–44.9 μg/dl, ≥45 μg/dl respectively. A child that is diagnosed with moderate or severe lead poisoning should be considered to receive chelation therapy (The Ministry of Health of People’s Republic of China, 2006).

2.1. Case 1- Lead exposure from tin wine pot

Two siblings (5-year-old brother, 10-year-old sister) from Yiwu in Jinhua City of the Zhejiang Province were brought to the hospital where their cases were collected. They presented with behavioral symptoms including hyperactivity and shortness of temper. The children appeared visibly pale, although they had no other obvious physical symptoms. The BLLs of the brother and the sister tested at the local hospital were 15.0 μg/dl and 28.5 μg/dl, respectively. At that time, they did not receive any treatment. The sister and brother were seen three months later because their symptoms persisted. Then their BLLs were tested again showing 14.5 μg/dl of the brother and 26.2 μg/dl of the sister, which was the basis of the diagnosis of childhood lead poisoning. The patients’ family history revealed that they did not live in or around an industrial zone and the parents had never worked in any factories with possible lead exposure. The other members of the family also had their BLLs tested and all showed elevated levels: the grandfather: 32.7 μg/dl, the mother: 15.0 μg/dl, the father: 35.0 μg/dl, which suggests the presence of a common lead exposure source in the family. Upon further questioning, the doctor found that the family had been cooking with yellow rice wine contained in a tin wine pot. In their hometown, people traditionally poured yellow rice wine into a tin wine pot, which was then poured into cups or over the ground as a sacrificial offering or libation to their ancestors. The patients’ family followed this tradition and usually used the sacrificial wine left in the tin pot for cooking in the week following the sacrificial rites. When the wine was used up, the tin pot was put away until the next sacrificial rite. Sometimes, however, tin pot would continue to be used as a household container to hold the yellow rice wine for seasoning. Since tin pots have been known to be contaminated by lead during the process of production and other family members also had elevated BLLs, the doctor suspected that the tin wine pot was the primary lead exposure source in the documented lead exposure assessment. Based on their diagnoses, the siblings were then treated with chelation therapy with calcium disodium versenate (CaNa₂EDTA) and/or prescribed calcium, zinc, and iron supplements (Table 1). The doctor also recommended that the family stop using the tin pot to contain anything used for cooking. The information about other cultural practices such as tinfoil burning, which might serve as an additional exposure source, was also shared with the family. The children’s parents both stated that they understood the risks of using the tin pot to contain cooking wine after the doctor provided education of the risk and would take the doctor’s suggestions. The follow-up BLL results two months after treatment showed the boy’s and the girl’s BLLs had declined to 11.65 μg/dl and 13.35 μg/dl respectively and they both had behavioral improvements.

Table 1.

Case summary

	Region	Age(years)	Gender	Symptoms and signs presented by the patient	Child’s BLL tested before treatment	Possible lead exposure source	Rationale for the doctor’s evaluation of lead exposure sources	Treatment history before coming to our hospital	Treatment for children at our hospital	Child’s BLL post-treatment
Case 1a	Yiwu,Jinhua, Zhejiang Province	5	Male	Hyperactivity, shortness of temper, pale	14.5 μg/dl	Tin pot	(1) No family history of industrial or occupational lead exposure. (2) Elevated BLLs among other family members: grandfather: 32.7 μg/dl. mother: 15.0 μg/dl; father: 35.0 μg/dl. (3) Use of a tin pot that was known to be lead contaminated as a container of rice wine for cooking,	He hadn’t received any treatment.	Calcium, zinc, iron and vitamin supplement	11.65 μg/dl
Case1b	Yiwu, Jinhua, Zhejiang Province	10	Female	Hyperactivity, shortness of temper, pale	26.2 μg/dl	Tin pot	Same with Case1a.	She hadn’t received any treatment.	Chelation therapy; calcium, zinc, iron and vitamin supplement	13.35 μg/dl
Case 2	Xiaoshan in Hangzhou, Zhejiang province	6	Male	Aggressive behaviors, limited language use, and frequent constipation	27.3μg/dl	Tinfoil home factory	(1) The family were exposed to lead with elevated BLLs: grandmother: 28.0 μg/dl; grandfather: 60.0 μg/dl. (2) Such a tinfoil home factory where the family were living and working was known to be a lead exposure source.	He hadn’t received any treatment.	Chelation therapy; calcium, zinc, iron and vitamin supplement	20.9 μg/dl
Case 3	Changchun, Jilin	8	Male	Hyperactivity, attention deficiency, and grumpiness	50.0 μg/dl	Folk medicine	(1) No family history of industrial or occupational lead exposure. (2) No elevated BLLs among other family members: mother: 4.8 μg/dl. (3) Some components in the folk medicine used to treat oral ulcers and diarrhea had been determined to be lead compound.	He had received treatment with unspecified medicines without alleviation of symptoms.	Chelation therapy	13.3 μg/dl

2.2. Case 2- Lead exposure From Tinfoil Home factory

A 6-year-old boy from Xiaoshan in Hangzhou City of Zhejiang province came to see the doctor after being diagnosed with lead poisoning for over three years. The patient was initially admitted to a local hospital at 2 years of age after presenting with aggressive behavior, limited language use, and frequent constipation. His BLL tested at the local hospital was 31.0 μg/dl and he did not receive any treatment. Since the symptoms persisted, he travelled to the hospital in Shanghai seeking treatment and his BLL was re-tested, showing 27.3 μg/dl. After detailed inquiry, it was revealed that during the last 10 years, the family maintained a small home factory for producing tinfoil used in ceremonial burning, which was suspected as the source of lead exposure. The raw materials used to produce the tinfoil were tin ingots which contained 50%−60% lead and most of the production processes were completed by hand instead of by machine, allowing for skin contamination (Jinbin, Xiaoqing, Huifen, & Hui, 2012). The factory was located on the first floor of the patient’s house and the family’s living space was located on the second and third floor. There was no ventilation or dust removal equipment in their home factory and none of the workers used effective personal protection equipment. The BLLs of the patient’s family members were also tested and found to be abnormally high. The grandmother, who did not directly work in the factory, had a BLL of 28.0 μg/dl. The grandfather, who worked in the factory, was found to have a BLL of 60.0 μg/dl. During her pregnancy, the mother stayed in the house and was likely to be exposed to the lead from the factory. The doctor collected the child’s birth history and developmental data and didn’t find clear signs of early complications from prenatal lead exposure. The possible lead exposure pathways for this patient were suspected to be the inhalation of lead-containing dust from the home factory, hand-to-mouth behaviors, and skin contact with lead-contaminated tinfoil, tin ingots and/or adults’ lead-polluted work clothes. The patient was treated with CaNa₂EDTA chelation therapy in the hospital, lowering his BLL to 12.8 μg/dl by the end of the treatment course. The doctor recommended that the family be moved away from the home factory and the family members take standard occupational protection measures during their work. The BLL of the patient in the most recent follow-up two months after treatment was 20.9 μg/dl, suggesting possible continued lead exposure.

2.3. Case 3- Lead exposure from Folk Medicine

An 8-year-old boy arrived at the pediatric lead clinic presenting with behavioral symptoms, including hyperactivity, attention deficiency, and grumpiness. His BLL was tested 18 months prior at another facility, showing 24.0 μg/dl. Parents reported that he received treatment in a nearby city but his symptoms were not significantly improved. Upon arrival to our hospital, his BLL was 50.0 μg/dl. The family history showed that no family members were involved in lead-related factory work and the patient’s home was not located in an industrial zone potentially exposed to lead, ruling out an industrial source. The BLLs of the boy’s parents were within the normal range according to the test results. Upon further inquiry, it was reported that the boy had been using a red powder folk medicine that was sprayed into the mouth and applied to the navel to treat oral ulcers and diarrhea for the last 5 years. This type of folk medicine commonly contains lead oxide and was suspected to be the primary source of lead exposure in this case. The patient last used this folk medicine for treating oral ulcers a month before arrival at the lead poisoning clinic. The patient was diagnosed with severe lead poisoning and was hospitalized 4 times to receive chelation therapy with CaNa₂EDTA at our hospital. His BLL dropped to 13.3 μg/dl in the most recent test. The doctor’s primary recommendation to the family was that they stop using any folk medicines immediately to avoid potentially continued lead exposure.

2.4. Case Summary Table

The information on the three cases was summarized in Table 1.

3. Discussion and Implication

Elevated blood lead levels in early childhood have been shown to be associated with increased risks for sleep problems (Liu et al., 2015), negative behavior in classrooms (Kordas et al., 2007), and attention-deficit/hyperactivity disorder (Nigg, Nikolas, Mark, Cavanagh, & Friderici, 2010) later in life. The lead exposure sources of all three cases presented here are preventable. Case 1 involved lead exposure from a traditional container made of a tin-lead alloy to contain yellow rice wine for cooking; Case 2 had exposure to lead from a home-factory that produced traditional tinfoil for ceremonial burning, and Case 3 involved the use of a folk medicine containing lead oxide. The guardians’ insufficient knowledge of potential lead exposure sources and the limited governmental policy and regulation of lead put the children at increased risks of lead poisoning and its detrimental long-term impacts. These cases draw attention to potential domestic sources of lead exposure that current health education, research and legislation have not fully considered. These cases demonstrate that assessing the full risk spectrum associated with neglected domestic exposure sources is necessary. The key information on implication strategies was presented in Table 2.

Table 2.

Key Implication Strategies

	Goal	Strategy	Outcome Measure
Risk Assessment	To best distribute educational resources to clinicians and families.	A national childhood blood lead screening should be performed to identify the high-risk regions. Surveys on both the undomestic and domestic lead exposure sources should be conducted within those high-risk regions. Geographic information systems can be in combination with these data. A standard questionnaire can be designed and applied in the clinical pathway for lead-poisoning diagnosis and treatment.	Identification of the high-risk regions in China. Identification of the undomestic and domestic lead exposure sources in the high-risk regions. A standard questionnaire for the clinical pathway.
Health Education	To help the parents identify potential sources of lead exposure and to minimize their children’s risks.	Health education can include information on sources of lead, health sequelae of lead, and lead exposure reduction strategies. The content should be tailored to reflect the most prevalent lead-exposure sources in each target region. Educational materials should not be limited to the hospitals, but also included in public announcements. People at high risk of lead poisoning should be the target group.	People’s knowledge on sources of lead, health sequelae of lead, and lead exposure reduction strategies
Policy Implementation	To make proper lead-poisoning treatment available for all the people and decrease child lead poisoning cases from exposure to tin pots, home factories producing tin foil, and folk medicine.	Measured efforts to train clinicians and public health nurses especially in high risk lead regions ought to be implemented by the government. Policy strategies can include legislation, regulation and surveillance, public notification, mass media and product labeling.	People’s accessibility to lead-poisoning treatment. A more effective regulatory framework of traditional Chinese medicine. National standards or industry standards about the production process or lead content of products.

3.1. Lead Exposure Risk Assessment

These three cases shed light on domestic lead exposure sources that vary from region to region based on common practices. For this reason, it will be vital to assess regional average blood lead levels and corresponding common exposure sources in order to best distribute educational resources to clinicians and families. In order to accomplish this, a three-step approach is recommended. First, since concrete data on the extent of childhood lead poisoning in China is limited, a national childhood blood lead screening could be performed in order to identify the high-risk regions. To determine feasibility, a pilot screening could be conducted first in one of the affected regions identified based on the geographic distribution of the patients coming to the pediatric lead poisoning clinic (Ying et al., 2018). Second, surveys on both the non-domestic and domestic lead exposure sources could be conducted within those high-risk regions by the public health nurses. Cultural factors should be taken into consideration when the regional lead exposure sources are identified. For example, both Case 1 and Case 2 presented here came from Zhejiang Province, where the residents have cultural traditions of using tin pots to hold wine and burning tinfoil during sacrificial rites for ancestors. Evaluating the potential lead sources specific to particular regions can help the nurses and clinicians better understand the regional landscape of high-risk factors for childhood lead poisoning and provide the information necessary to tailor preventative measures. Geographic information systems can also be used in combination with these data to create models to identify potential lead exposure sources and high-risk areas in China. This has previously been a feasible and effective strategy in the US (Kim, Galeano, Hull, & Miranda, 2008; Reissman, Staley, Curtis, & Kaufmann, 2001). Finally, based on the risk factors identified in different regions of China, a standard questionnaire can be designed and applied in the clinical pathway for lead-poisoning diagnosis and treatment, similar to the Pediatric Lead Screener Questions recommended by US Centers for Disease Control and the American Academy of Pediatrics. This could help the clinic nurses and doctors determine individual patient’s possible lead exposure sources, especially for clinicians lacking experience in lead poisoning treatment.

3.2. Health Education

Health education is crucial to the prevention and treatment of lead poisoning. Parental education can be incorporated in a primary care setting. During the child’s routine visit to the pediatrician, nurses can provide pamphlets in the appointment and/or educational videos repeatedly broadcasted by TVs in the waiting room to increase the parents’ knowledge about the consequences and sources of childhood lead poisoning. During the physical examination, health education can be part of the regular procedure. There is a need for more information sources for parents to help them identify potential sources of lead exposure and minimize their children’s exposure and risks (Porter & Severtson, 2000). In addition, social media platforms such as WeChat are very popular and almost universally available to all the adults in China. They have been demonstrated as an effective way to disseminate medical knowledge and preventative information. Nurses or doctors could post the health education content on the hospital’s WeChat public account regularly to provide all of the people who have subscribed with consistent and accurate information. Public health nurses are qualified to provide these education measures because of their background understanding of the lead exposure status among their populations and communities. This health education can include information on sources of lead, the health sequelae of lead, signs of lead poisoning, and lead exposure reduction strategies, such as household cleaning, safe use of water, proper hygiene, and nutrition (Pfadenhauer, Burns, Rohwer, & Rehfuess, 2014). The educational content should be tailored to reflect the most prevalent lead-exposure sources in each target region, along with general prevention recommendations. For example, for Case 1 and Case 2, visual representations of tin-wine containers ought to be included in the educational materials along with recommendations to clearly label them for ceremonial and not culinary use, recommendations for tinfoil burning to be performed outdoors or in well ventilated spaces, as well as reliable places to purchase non-contaminated foils could be outlined. Moreover, people should be instructed to dispose of ashes safely and wash their hands thoroughly after performing the practice. These educational materials should not be limited to the hospitals, but also included in public announcements such as posters distributed to be kept in the home and in public locations.

People at high risk of lead poisoning, such as children up to six years of age and pregnant women, should be the groups primarily targeted by public health nurses. For women, education about potential lead exposures should begin prior to pregnancy and protective measures and educational campaigns should be implemented in both the workplace and the home. The adults that must be involved in lead-containing workplaces for economic sustenance should be encouraged to shower and change clothes immediately upon finishing the task before contact with children and launder the work clothes separate from family clothes.

3.3. Practical Implications

In all three of these cases, the patients had to travel long distances to reach the hospital where we collected these cases because their local hospitals were not outfitted for proper lead-poisoning diagnosis and treatment of children, or they lacked the medicines and/or experience in treating lead poisoning. The government should support the hospitals in less developed areas of China in becoming equipped with the infrastructure necessary to screen for lead poisoning, such as Inductively Coupled Plasma Mass Spectrometry (ICP-MS), a machine that can measure BLL as well as the concentrations of other elements in the blood. Measured efforts to train clinicians and public health nurses regions ought to be implemented by the government, especially in high-risk areas. The training about how to prevent, diagnose and treat childhood lead poisoning should be increased in medical undergraduate education programs and the related continuing education and training programs for pediatricians should be developed extensively, especially for those working in the less developed and remote districts.

Moreover, the tinfoil home factories like that in Case 2 in Zhejiang Province have been very popular since 1990s (Huifen, Fuyun, Jinbin, & Da, 2010). According to an investigation conducted among 38 families producing tinfoil at home in Jinhua, Zhejiang Province, it was common that all the family members including children lived in the home factories, which had no ventilation facilities, dust removal equipment, or effective personal protection equipment. Additionally, the processing technique was mostly completed by hand and there were no protection measures taken to reduce exposure. 97.78% of the children from these families had BLL ≥10 μg/dl. Among five home factories sampled randomly, the lead concentrations in dust or smog in all the worksites for melting tin ingots and beating the foils were beyond the Occupational Exposure Limits for Hazardous Agents in the Workplace Part 1 Chemical Hazardous Agents (GBZ 2.1–2007, national occupational health standards issued by the Minister of Health of the People’s Republic of China) and lead was found in all the kitchens and bedrooms (Jinbin et al., 2012). Although the government has shut down many home factories, screened the BLLs of local residents, and monitored the surrounding environment, as far as we know, no national standards or industry standards about the production process or lead content of tin-foil have been issued. In addition, other childhood lead poisoning cases due to lead-contaminated or lead-added traditional Chinese medicine or folk medicine such as those used in Case 3 have been reported in recent years (Lin, Wu, Yan, Li, & Liu, 2012; Tang, Tu & Feng, 2017; Ying, Xu, Markowitz, & Yan, 2016). In both Ayurvedic and traditional Chinese medicine, due to some short-term beneficial properties of lead such as the decrease of swelling and convergence effects, lead and its compounds have been incorporated in the treatment of diverse diseases including ulcers, epilepsy, and parasitic infections. Most qualified clinicians in China have been aware of the toxicity of lead. The production and sale of traditional Chinese medicine in China requires certifications and the individual practitioners are prohibited from making and selling uncertified traditional medicine (Tang et al., 2017). However, the reality is that many traditional and folk medicine practitioners have been practicing without certification and a large number of Chinese people believe in the effects of folk medicine, especially in rural areas, which makes it challenging to control this source of lead exposure.

Policy strategies to mitigate childhood lead exposure can include legislation, regulation and surveillance, public notification, mass media and product labeling. Policies need to be enacted to set standards for industries that may impose risks of lead exposure on the working staff and to encourage the enterprises to improve production techniques so that the lead contamination can decrease (Yan et al., 2013). It is necessary for the government to speed up legislation to construct a more effective regulatory framework of traditional Chinese medicine, including folk medicine. Moreover, product labeling, such as labeling the appropriate use of ceremonial tinfoil and tin pots, can also assist consumers in understanding the potential risks of lead exposure. With proper quality control and effective accessibility measures, media sources like print, radio, television, and official public notifications can improve the public’s knowledge about lead poisoning.

4. Conclusions

Childhood lead poisoning continues to be a global issue. The nonspecific symptoms of lead poisoning and lack of awareness of its various sources make it difficult to diagnose, often delaying treatment and resulting in major neurological symptoms. The three cases presented highlight that domestic sources of lead exposure are noteworthy in China and warrant action. Lack of lead exposure risk assessment, insufficient knowledge of potential lead exposure sources, limited policy and regulation are challenges in preventing childhood lead poisoning. Since the childhood lead poisoning cases from domestic products occur in the communities, public health nurses are at the frontline of appropriately assessing lead exposure risks, providing health education, conducting research, and advising the government to apply policy strategies to mitigate childhood lead exposure.