Identifying contextually relevant lead exposures and risk practices/behaviors in Botswana and assessing caregiver lead knowledge levels

Abstract

Lead poisoning accounts for about 0.6% of the global burden of the disease; however, lead poisoning is under researched in low- and middle-income countries. We conducted this study to assess the risk factors associated with lead exposures, and we also assessed lead knowledge levels among caregivers of children under the age of 6 years. We administered a survey to 145 caregivers to collect demographic, socio-economic, housing and lead exposure information, and administered the validated Chicago Lead Knowledge Test (CLKT). Chi-square tests were used to describe the association between housing characteristics. 70 %, 55 % and 49 % of caregivers, respectively, reported seeing their children place these objects into their mouths, keys, jewelry and soil. Sixty-three percent of the respondents reported living near a busy road, and 46 % of the respondents reported visibly damaged paint in their homes. An association was observed between age of home and presence of damaged paint (P-value = 0.04). The median score on the CLKT was 50%. Over 50% of the participants incorrectly believed that most cases of childhood lead poisoning are caused by drinking water that contains lead, and 39% of the participants believed lead could be removed from water by boiling. These incorrect responses suggest the need to design interventions to increase awareness of sources of lead. Based on the high prevalence of risk factors for lead poisoning and the low lead knowledge score of caregivers, it may be beneficial to design education interventions to address knowledge gaps and empower individuals to prevent childhood lead exposure.

Keywords:

• Lead exposures
• awareness
• parents/caregivers
• children
• Gaborone Botswana

1. Introduction

Lead is a naturally occurring heavy metal that is present in everyday objects and environments and is considered to be one of the most harmful chemicals to humans (Agency for Toxic Substances & Disease Registry, 2020). When ingested or inhaled, lead can result in elevated blood levels associated with morbidity and can be fatal. Young children are more susceptible to the effects of lead exposure because of their repeated hand-to-mouth behavior, the direct interaction of lead with their developing nervous systems, and the higher rate of gastrointestinal absorption of lead (Lanphear et al., 2002; Ziegler et al., 1978). Lead poisoning, a preventable condition, causes multiple developmental issues including behavioral problems, learning disorders, poor academic performance, growth delays, exhaustion, and other physical conditions such as convulsions, and muscular paralysis (Daley et al., 2018; McFarland et al., 2021; Needleman et al., 1996; Reuben et al., 2019; Schwartz, 1994); many of these health issues are thought to be irreversible. Common childhood lead exposures include soil, lead dust from lead-based paint and toys (Centers for Disease Control and Prevention, n.d).

In Botswana, a blood lead survey conducted among children under the age of 7 years showed that blood lead levels ranged from 1.6 to 28.6 µg/dL. The study reported that 31% of the children had blood lead levels exceeding 10 µg/dL (Mbongwe et al., 2010), which was the Centers for Disease and Control Prevention (CDC) reference value for blood poisoning at the time. It is imperative to identify lead sources in this context and hence design appropriate preventive interventions. Sources of lead include legacy sources such as lead-based paint dust and soils; and more contextually relevant sources such as food products, traditional herbal remedies and cottage industries (Asomugha et al., 2016; Kootbodien et al., 2012; Mathee et al., 2020; Orisakwe et al., 2019; World Health Organization, 2021b).

Caregiver lead and lead poisoning knowledge levels and/or a high-risk perception are good predictors for lead prevention practices (Jordan et al., 2007; Kegler & Malcoe, 2004). However, lead poisoning knowledge levels have been reported to be low in several settings (Adebamowo et al., 2006; Haman et al., 2015; Mathee, 2014). In Botswana, no studies have been conducted to evaluate the lead knowledge levels of caregivers of children under the age of 6 years. Assessing the knowledge levels specific to lead poisoning exposures, effects and prevention can inform and guide the design of interventions aimed to address existing knowledge gaps or inaccuracies and encourage prevention action. Several educational interventions have resulted in increased awareness about lead poisoning and promoted primary prevention including residential lead remediation and secondary prevention behavior such as screening for elevated blood levels (Kegler & Malcoe, 2004; Schultz et al., 1999).

The World Health Organization (WHO) acknowledges that unless the prevalence and sources of lead are known in a setting, it is challenging to develop effective preventive measures. A single study conducted in Botswana in 2010 revealed that 31% of children 6 years and younger had blood lead levels ≥ 10 µg/dL (Mbongwe et al., 2010). However, no study has assessed caregiver knowledge levels in Botswana; therefore, this study aims to identify potential contextually relevant sources of lead poisoning in Botswana and to evaluate the lead poisoning knowledge levels of caregivers in Botswana.

2. Materials and methods

2.1. Setting

This study was conducted in Gaborone, the capital city of Botswana, a middle-income country in Africa. Botswana provides affordable universal health care to all citizens through a public healthcare system, but citizens may choose private health facilities usually financed through their employers. Children under the age of 5 years can attend free periodic health and wellness visits at the public healthcare facilities for immunization and nutritional supplementation.

2.2. Recruitment and ethical considerations

Individuals eligible for inclusion in the study were i) over the age of 18 years and visiting the clinic to bring a child under the age of 6 years to a wellness visit, or were over the age of 18 years, a caregiver of a child under the age of 6 years old but attending the clinic for their own personal health check; and were ii) able to speak either English or Setswana. Participants signed a written consent in either English or Setswana and retained a copy for their own record.

Participants for this study were recruited from the following health care facilities in Greater Gaborone: Bontleng Clinic, Broadhurst 1 Clinic, Extension 2 Clinic, Julia Molefhe Clinic, Mafitlhakgosi Clinic, Old Naledi Clinic, Princess Marina Hospital pediatric ward, and Village Clinic. The consent process was conducted for all interested and eligible individuals. The study materials including the consent form were approved by the Institutional Review Board of the Health Research & Development Committee in the Ministry of Health in Botswana and by the Gaborone District Health Management Team in Botswana permitting recruitment in the clinics.

2.3. Data collection

All consenting participants responded to two questionnaires; the first one collected some demographic information (age of child, age of caregivers, caregivers’ education level, employment status and income level) and included questions specific to lead poisoning risk factors and practices in Botswana. The risk factors included in the questionnaire were informed by peer-reviewed articles documenting potential sources of lead in a neighboring country (Mathee et al., 2007, 2020; Mathee, 2014) and a contextual understanding of practices in the setting.

The second questionnaire was the validated 22-question Chicago Lead Knowledge Test designed to evaluate general information about lead (Questions 2, 3, 4, 5 and 14); lead exposures (1, 6, 10, 18, 17, 15, 19, 16, 12, 21,20); lead poisoning preventive practices (7, 13, 11, 8); and nutrition (22, 9) (Mehta & Binns, 1998). Participants had the option to complete the self-administered questionnaire in either English or Setswana. Researchers were available to answer any questions that arose as participants completed the questionnaire or to administer to caregivers who preferred the researcher-administered option of data collection.

2.4. Data analysis

All data were entered into Excel and imported into Stata version 14 for analysis (StataCorp, 2015). Using counts and frequencies, data on the prevalence of lead poisoning risk factors were summarized. The risk factors included the age of home, the proximity of the home to a busy street, living with relatives who have a profession in painting and/or car battery manufacturing, children eating soil, and the use of traditional herbal remedies.

To analyse the Chicago Lead Knowledge Test, a test score was obtained for each respondent. Correct responses received a score of 1. Incorrect and “Don’t know” responses received a score of 0. Total scores ranged between 0 and 22; any skipped questions were considered to correspond to a “Don’t know” response. A higher score is indicative of higher knowledge levels.

For continuous data, normality was assessed using the Shapiro–Wilk test, and variables were described appropriately with the mean and standard deviation or with median and interquartile range. The Chi-square test was used to describe the association between the following variables: age of home and presence of chipping, peeling and cracking paint; and soil consumption and knowledge of lead in soil. We hypothesize that older homes are associated with the presence of deteriorated paint and that caregivers who have witnessed their children eating soil are less likely to identify soil as a source of lead.

3. Results

The median age of the 145 participants was 29 years (IQR 25–35; range 18–73). Only 5 (3.5%) participants indicated that their child had received a blood lead test. The median age of the children of the participants was 19 months (IQR; 11.25–43.5) and ranged from 1 to 77 months. Other demographic characteristics of the sample are presented in Table 1.

Table 1. Demographic, socio-economic and housing characteristics of the sample

Variable	Categories	N (%)
Gender of parent/caregiver	Female	128 (84.8)
	Male	23 (15.2)
Education Level Female parent/caregiver	No formal schooling	2 (1.4)
	Primary school	13 (9.3)
	Secondary	59 (42.1)
	Tertiary	66 (47.1)
Education Male parent/caregiver	No formal schooling	3 (2.3)
	Primary school	14 (10.5)
	Secondary	53 (39.9)
	Tertiary	63 (47.4)
Income (BWP)	Less than P1,000	19 (17.4)
	1,000–2,500	31 (28.4)
	2,501–5000	21 (19.3)
	5,001–10,000	19 (17.4)
	10,001–15,000	7 (6.4)
	15,001–25,000	8 (7.3)
	>25,0000	4 (3.7)
Decade when home was built	Before 1980	23 (18.0)
	1980–1990	22 (17.2)
	1991–2000	22 (17.2)
	2001–2010	28 (21.9)
	2011 – 2019	27 (21.0)
	Don’t know	6 (4.7)
Duration of residence in current home	Less than 1 year	19 (14.7)
	1–5 years	61 (47.3)
	6–10 years	18 (14.0)
	10–15 years	6 (4.7)
	16–20 years	7 (5.4)
	>20 years	18 (14.0)
Visible peeling, cracking, chipping paint in home	Yes	65 (45.8)
	No	77 (54.2)

Note: Missingness varied from less than 1 % for gender to 25 % for income.

About 75% of the respondents indicated living in a home that was built before and including 2010 and there was a significant association observed between the age of home and the presence of cracking, chipping, and peeling paint (P-value = 0.041). Over 60 % of the respondents reported living in their homes for less than 5 years. However, there was no association between the length of residence in a home and the decade in which the home was constructed (P-value = 0.354).

Several risk factors for lead poisoning were observed as shown in Table 2. The most prevalent risk factors were living next to a busy road (currently or ever) and the child placing keys or jewelry in their mouths. Other risk factors that involve ingestion, and moderately prevalent, were eating soil, and sucking fingers. Risk factors related to employment and leading to secondary lead exposure in children such as car battery manufacturing, car repair, or painting were minimally prevalent.

Table 2. Prevalence of lead exposures and risky practices in Gaborone, Botswana

Behaviors/Practices	Prevalence
Does your child suck any of his/her fingers?	42.8
Have you ever observed your child eating soil?	48.6
Have you ever observed your child eating paint chips?	18.8
Have you ever observed your child putting keys in his/her mouth?	70.3
Have you ever observed your child putting jewelry in his/her mouth?	55.4
Does your child live with a relative who paints houses?	15.9
Does your child live with a relative who works in a place where car batteries are made?	8.3
Does your child live with a relative who repairs cars?	16.1
Do you have any old vehicles in your yard?	23.5
Does your child consume any traditional herbal remedies?	12.7
Is there any peeling, chipping or cracking paint in your home?	45.8
Do you currently live close to a busy road?	63.1
Since this child was born, have you ever lived next to a busy road?	54.0

The median score on the CLKT was 11 (IQR 9,13). The frequencies for correct responses are shown in Table 3. The three questions with the highest frequency of correct responses were No 3 (81.5% correct), No 7 (81.1% correct), and No 6 (76.0% correct). Two of these questions are directly related to lead-based paint. The third question that focuses on lead poisoning prevention is a basic hygiene question. The three questions with the highest frequency of incorrect responses were No 12 (51.0% incorrect), No 11 (39.2% incorrect) and No 1 (38.6% incorrect). Two of these questions are related to lead exposures in water and the other one assesses the risk of lead based on housing age.

Table 3. Shows the Chicago lead knowledge test questions, the correct response and the corresponding percentage of each response option for each question

No	Statement	Correct Response	Correct	Incorrect	Don’t Know
1	Lead paint is more likely to be found in newer homes than in older homes.	False	18.8	38.5	43.4
2	High lead in the body can affect a child’s ability to learn.	True	62.1	5.5	32.4
3	Lead paint chips can be poisonous when eaten.	True	81.8	1.5	16.8
4	A child’s highest blood lead level generally occurs around 5 years of age.	False	9.1	25.9	65.0
5	Most children have symptoms right away if they have an elevated blood lead level	False	8.9	32.9	58.2
6	Living in a building during renovation/remodeling can increase a child’s exposure to lead.	True	76.0	3.4	20.6
7	Washing a child’s hands often helps prevent lead poisoning.	True	80.7	4.8	14.5
8	Cleaning a home with soap and water decreases the lead in the home more than dusting or sweeping.	True	66.0	9.7	24.3
9	A diet with a good amount of iron-containing foods will help decrease a child’s chance of becoming lead poisoned.	True	44.5	13.0	42.5
10	One way for children to get lead poisoned is by having lead dust on their hands and then putting their hands in their mouth.	True	75.3	6.9	17.8
11	Lead in water can be removed by boiling.	False	14.0	39.2	46.9
12	Most cases of childhood lead poisoning are caused by drinking water that contains lead.	False	13.1	51.0	35.9
13	Warm tap water usually contains less lead than cold tap water.	False	12.9	34.7	52.4
14	Apartment owners are required to tell renters about known lead-containing paint in the apartment when a lease is signed.	True	52.8	10.4	36.8
15	Parents who work with lead at their jobs can bring lead home on their clothes	True	66.9	8.3	24.8
16	Lead in soil cannot harm children.	False	59.9	17.0	23.1
17	Some pottery imported from Mexico or other countries is not safe to use in cooking or for eating, because it contains lead.	True	27.8	13.2	59.0
18	A child can become lead poisoned during exposure to lead-containing dust.	True	75.2	5.5	19.3
19	The lead a pregnant woman takes into her body can be transferred to the unborn baby.	True	50.7	10.3	39.0
20	Some herbal or traditional home remedies contain lead.	True	37.1	15.4	47.6
21	Most children get lead poisoned by breathing in lead, rather than by eating or swallowing lead	False	21.8	34.7	43.5
22	The human body needs a small amount of lead for good nutrition.	False	19.7	32.0	48.3

The percent of “Don’t know” responses ranged from 14.5 % (Question 7) to 65.0 % (Question 4) indicating that a significant proportion of the participants did not know the responses to the questions. The three questions with the highest frequency of don’t know responses were No 4 (65.0%), No 17 (59.0%) and No 5 (58.2%). Question 17 addresses a lead exposure that is not relevant to the context of Botswana. The other two questions addressed the direct impacts of lead on children.

Comparing caregivers who correctly indicated that lead in soil can harm children to those who incorrectly answered this question, there was no significant difference in the prevalence of the children consuming soil (χ² = 0.24, p-value = 0.62).

4. Discussion

Behaviors and practices associated with a heightened risk of lead exposure are prevalent in Botswana. Over three fifths of respondents lived near busy roads and almost half of the respondents reported seeing their child eats soil. Botswana is a highly mineralized country and therefore likely to contain high levels of lead in soil. Although Botswana eliminated the use of leaded gasoline in 2006 (Ritchie, 2022), studies have shown that soil lead deposits from vehicles can continue to harm young children for years after the discontinuation of leaded gasoline (Mielke & Reagan, 1998). Particularly, the soils in the city of Gaborone have been shown to contain lead (Mbongwe et al., 2010; Zhai et al., 2003). Efforts need to be made to quantify the lead in soils, and if necessary design appropriate methods to remediate the soils, especially those close to roads that were considered busy prior to 2006.

Botswana has a limited manufacturing industry and therefore imports most of its paint from South Africa. Because of the South African lead paint regulation, it is unlikely that any paint currently imported from South Africa into Botswana will have high levels of paint. A recent study (Lead Exposure Elimination Project, 2021) reported lead quantities in paint samples from Botswana in the range of 86–100 ppm (the limit is 90 ppm; 100ppm is the reporting level and 90 ppm is the internationally recommended limit). However, paint used in homes built before 2010, when South Africa banned lead-based paint might have contained high levels of lead (Government of South Africa, 2009). More than half of the participants lived in homes built before the 2010. Almost half of the study participants reported seeing peeling, chipping and cracking paint. In our study, we observed a statistically significant association between visible paint disrepair and age of homes, suggesting a potential higher risk of lead exposure among residents of older homes. Studies conducted in South Africa prior to the lead in paint ban detected lead in samples; in 2007 lead was detected in 83% of enamel-based paint (Mathee et al., 2007) and in 17% of paint chip samples collected from homes (Montgomery & Mathee, 2005).

The use of traditional medicines on the African continent is prevalent; WHO predicts that 80% of the African population uses traditional medicine (World Health Organization, 2002). However, traditional medicines can be a source of lead (Mathee et al., 2015; World Health Organization, 2015). A study in Botswana showed that some traditional medicines contained several metals including lead (Okatch et al., 2012). In this current study, we report that one eighth of the participants reported using traditional herbal medicines for their children. It would be beneficial to inform caregivers of the potential presence of lead in herbal remedies. A review of lead encephalopathy due to traditional medicines focusing on Asia, the Middle East and South America showed that most cases of encephalopathy were pediatric in nature and some cases were fatal (Karri et al., 2008). Additional research needs to be conducted in Botswana to identify which remedies might contain lead.

Consistent with studies conducted in several countries, the lead knowledge levels of caregivers in Botswana are low. A median score of 50% was attained in this study of caregivers of children under the age of six. Studies on the African continent reveal similar findings; in Johannesburg, a study of pregnant women identified that only 11% of the participants had heard of lead poisoning (Haman et al., 2015). A qualitative study in Nigeria revealed that several of the participants were unaware of domestic sources of lead (Adebamowo et al., 2006). Low caregiver knowledge levels about lead hazards suggest a limited ability to protect children from lead exposures. Educational interventions can be developed guided by the results of the Chicago Lead Knowledge Test, particularly the questions to which participants responded incorrectly or/and with a “Don’t know” response. The Tribal lead curriculum -Lead Awareness in Indian Country: Keeping our children healthy from the Environmental Protection Agency is an example of a curriculum that can be modified for contextual relevance and cultural appropriateness (Environmental Protection Agency, n.d).

A minority of respondents reported that their child had received a blood lead test and yet a study in 2010 quantified blood lead levels in children under the age of 6 to be in the range of 1.6 to 28.6 µg/dL; 31% of children in that study had elevated blood lead levels defined as 10 µg/dL (Mbongwe et al., 2010). Similar to the global setting, Botswana has no policy or regulation in place to screen blood lead levels. It is therefore likely that children with elevated blood lead levels are missed and are experiencing the harmful effects of lead. According to the national schedule for vaccines in Botswana, children receive the first and second dose of the measles vaccine at 9 and 18 months after birth (World Health Organization, 2021a) with an immunization rate of 97% and 76%, respectively (Statista, 2021). It maybe practical and feasible to add lead screening to these visits.

4.1. Limitations

A significant limitation of this study was that the respondents to the survey who had brought the child to the clinic were not necessarily the parents of the child. And yet information on educational levels was only collected for the parents and not the questionnaire respondents. This limits the applicability of these findings to tailored interventions. However, since the survey respondents were involved in the caring of the child, the findings on the knowledge levels are still relevant and can be used for designing generic interventions.

The Chicago Lead Knowledge Test used in this study has not been validated in this setting and, therefore, might not provide accurate results; however, since some of the questions are generic the results provide a general overview of lead and lead poisoning knowledge levels. Question 17 on this test would not necessarily be relevant in Botswana and the high proportion of “Don’t know” responses suggest validity in the responses. A small sample size was utilized in this study, and therefore these findings should be interpreted with caution and may not be generalizable. In addition, the responses were self-reported and might be prone to bias.

5. Conclusion

A high prevalence of some practices and behaviors placing children at risk of lead poisoning such as consumption of soil, placing keys and jewelry in the mouth, and living near busy roads were identified in Botswana. Enacting a policy or regulation to screen blood lead levels of children during routine wellness visits at 9 and/or 18 months of age may identify children who are exposed to lead and to intervene appropriately. In addition, using the Chicago Lead Knowledge Test, parents/caregivers attained a low score of lead and lead poisoning knowledge. Knowing the practices and behaviors that result in minimizing lead exposure can help parents/caregivers prevent childhood lead poisoning. Therefore, it may be beneficial to design informative and widespread interventions that would encourage individuals to be more aware of sources that can cause lead poisoning in children.

Acknowledgments

We would like to acknowledge the clinical staff who assisted by providing warm handoffs of study participants to research assistants and for providing spaces for survey administration. We would like to appreciate the following research assistants and personnel who were vital to the execution and completion of the project: Beauty Queen Dema, Refilwe Primrose Molemi, Obakeng Tahla, Letang Motsumi, Lame Basadi Montwedi, Joyce Gosetsemang Makoti, Fatima Maria Ratlou, Tirelo Puso, Thabang Tsele, Gaone Moetse, Susan Okatch, Katlego Michelle Maphorisa, Kaone Ditshai, Lesego Tshegofatso Sethaile.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was funded by college funds at Franklin and Marshall College; Hackman Summer Scholars Awards, Huffnagle Scholarship, and Mehlman Scholars Enrichment Experience Funds.

Notes on contributors

Harriet Okatch

Harriet Okatch is an assistant professor of public health at Thomas Jefferson University. Her primary research focusses on understanding the factors that contribute to elevated blood leads and identifying strategies to prevent lead exposure.

Chabaesele Makoti

Chabaesele Makoti is a final year at the University of Botswana majoring in Physics and Mathematics. He has a passion of community work.

Anuj Ghimirey

Anuj Ghimirey is a dental student at Temple University in Philadelphia and has contributed to several research projects to identify sources of lead in both Botswana and in Lancaster.

Hoi Lam

Hoi Lam is going into medical school and in her undergraduate studies, completed several projects on lead poisoning prevention including quantifying lead in soil and spices.

Jaala-Jasmyne Nkala

Jaala-Jasmyne Nkala is a senior majoring in Biology and Psychology with a minor in studio arts. She quantified lead in soil and contributed to efforts to increase awareness about residential lead remediation funding in Lancaster.

Najeda Regis

Najeda Regis is completing a Master’s in Public Health (Epidemiology) at Drexel University in Philadelphia and has completed research projects focussed on lead and on iron.