Developing a clinical assessment tool for screening lead exposure levels during pregnancy and after delivery

Lead is a toxic heavy metal associated with adverse health effects ranging from developmental neurotoxicity to reproductive effects. While lead affects people of all ages, infants and children are the most vulnerable and susceptible to the neuro-developmental effects of lead exposure. Maternal blood lead concentrations that do not produce clinical toxicity on pregnant women have been linked to adverse offspring development. Observed reproductive effects to low lead levels during pregnancy include the risk of spontaneous abortions, effects on birth weight and preterm birth. There are particular concerns with regard to reductions in IQ scores. Research evidence suggests that an incremental increase in blood lead levels of 1 µg/dL is associated with approximately 1 IQ point deficit. Of particular concern is that currently no threshold has been observed or exists for developmental neurotoxicity to the chronic low lead exposures levels. While the developed countries have built evidence for lead exposure sources, have identified the most vulnerable groups to lead exposure, and have instituted control actions for lead exposure, it is not the case in developing countries such as Botswana. Currently, there is very little knowledge about the potential sources of lead exposure among different population groups not only in Botswana but also in most developing nations. There is also an evident limited knowledge on the behaviours and practices of different population groups that could potentially expose them to lead in developing countries. This thesis explores the following questions: i) Are there specific risk behaviours and practices peculiar to pregnant women in Botswana that could potentially expose them to lead? ii) What are the environmental lead concentration levels and their potential to expose pregnant women? iii)What are the blood lead concentrations at each stage of pregnancy and after delivery in Botswana and, iv) Can we use the information from these three questions to predict lead exposure levels during pregnancy and after delivery? v) Can we use the new information to a develop a policy dissemination brief to inform policy on lead exposure sources in Botswana, develop guidelines for health professionals for assessing and screening lead exposure levels during pregnancy and after delivery, develop an awareness leaflet for lead education? To address the specific risk behaviour and practices of pregnant women, a comprehensive validated risk assessment questionnaire was administered among 142 pregnant women during the first trimester of pregnancy (defined as 8-12 weeks) in four villages of different geographical settings and nomenclature (small/rural, major and semi urban). For purposes of this work the validation process involved obtaining information (from experts in the field and communities) relevant to the purposes of the study and to confirm that the tools employed for collection of data in all trimesters were suitable in terms of both construct and content. Data was collected between September 2009 and February 2010. To address potential environmental sources of lead exposure during pregnancy soil (n=28), water (n=28) and traditional cosmetic clay - letsoku (n=3) samples were collected in November 2010, February 2011 and May 2011 from the homes and in the vicinity of the study population to determine lead concentrations. To know baseline blood lead levels at each stage of pregnancy, blood samples were collected from September 2009 to February 2011 from pregnant women between weeks 8-12 (first trimester, n=137), 20-24 (second trimester n=126) and weeks 34-36 (third trimester n=106). Blood lead levels of women who completed the entire study from trimester on until after delivery (n=63) were then used to construct blood lead prediction models using statistical models. Pregnant women in the study area ingested non-food items such as soil, match sticks, pencil, chalk and animal feed such as bone meal (86%). Women applied used and unused car oils (in particular brake fluid) and other harmful substances for “treatment of skin conditions and for beautification purposes (74%). Older women (defined as 35 years in this study) were at a significantly higher risk to ingest soils (p<0.01). Mean (±SEM) lead concentrations in water exceeded the WHO drinking water quality standards nineteen fold (0.19±0.019 ppm (n=28) Major villages, had significantly higher Pb concentrations (p<0.05) in soils and water compared to small villages. Mean blood lead levels (±SEM) for the first, second and third trimesters were 1.96(±0.14)µg/dL, 2.49(±0.17) µg/dL, 2.66(±0.19) µg/dL respectively. Blood lead levels increases from the first to third trimester ranged from 1.6-5%. Blood lead concentrations significantly differed among locations (p<0.01). The highest concentrations were observed in women from smaller villages that were poorer (p<0.02). Pica, multiple risk behaviours/practices (engaging in two or more risk behaviours/practices), trimester of pregnancy, poor food supplementation and diet were predictors of blood lead levels ≥ 2µg/dL. There was a dose response relationship between supplement intake and an increase in blood lead levels. These findings suggest that pregnant women and their unborn babies could potentially be exposed to lead because of the environment in which they live, their economic status, lifestyle, behaviors and practices. Drinking water is a potential threat for lead exposure, not only among pregnant women, but other vulnerable groups such as infants and children. This study is the first in Botswana and one of the few in Africa to investigate lead exposure sources at each stage of pregnancy and after delivery. It is also the first to identify new potential lead exposure behaviors and practices such as the application of auto oils by pregnant women for treatment of skin diseases. The findings suggest the need to train health workers and equip them with the skills and knowledge to assess and screen women who could potentially be exposed to lead. Further, pregnant women need to be sensitized on potential lead exposure sources, to prevent lead poisoning. This study has been able to use the results to develop a policy brief for disseminating the results to decision makers, guidelines for utilization by health workers to screen lead exposure levels and an awareness leaflet for pregnant women. These have been validated and pretested at community and Government levels.Thesis (PhD)--University of Pretoria, 2013.School of Health Systems and Public Health (SHSPH)Unrestricte

Supercritical fluid extraction of pesticides in sediment from the Okavango Delta, Botswana, and determination by gas chromatography with electron capture detection (GC-ECD) and mass spectrometry (GC-MS)

The study reports supercritical fluid extraction (SFE) of pesticides in sediment samples from the Okavango Delta, the headwaters of which originate from Angola and traverse through Namibia into Botswana. An acetone modifier and fractional extraction by pressure ramping gave recoveries ranging from 55 to 86% for the 15 pesticides studied. Hexachlorobenzene (HCB), aldrin and 4, 4-dichlorodiphenyltrichloroethane (4, 4’-DDT) were identified at concentration ranges of 1.1 to 30.3, 0.5 to 15.2 and 1.4 to 55.4 μg/g, respectively by gas chromatography with electron capture detection (GC-ECD) and were unequivocally confirmed by gas chromatography time-of-flight mass spectrometry (GC-ToF-MS). The study indicated an increase of pesticide concentrations in the direction of water flow from the Panhandle (point of entry) to the lower delta. The results show that there are ramifications associated with activities either upstream or downstream; hence close monitoring is required for the long-term preservation of the delta.Keywords: organochlorine pesticides; sample preparation; modifier; static extraction; dynamic extraction; fractional extraction

Addressing the Challenge of P-Value and Sample Size when the Significance is Borderline: The Test of Random Duplication of Participants as a New Approach

The issue of borderline p-value seems to divide health scientists into two schools of thought. One school of thought argues that when the p-value is greater than or equal to the statistical significance cut-off level of 0.05, it should not be considered statistically significant and the null hypothesis should be accepted no matter how close the p-value is to the 0.05. The other school of thought believes that by doing so one might be committing a Type 2 error and possibly missing valuable information. In this paper, we discuss an approach to address this issue and suggest the test of random duplication of participants as a way to interpret study outcomes when the statistical significance is borderline. This discussion shows the irrefutability of the concept of borderline statistical significance, however, it is important that one demonstrates whether a borderline statistical significance is truly borderline or not. Since the absence of statistical significance is not necessarily evidence of absence of effect, one needs to double check if a borderline statistical significance is indeed borderline or not. The p-value should not be looked at as a rule of thumb for accepting or rejecting the null hypothesis but rather as a guide for further action or analysis that leads to correct conclusions

Nature and sources of poisoning in patients admitted to a referral hospital in Gaborone, Botswana : findings and implications

Background: Intentional poisoning is becoming an important public health concern particularly among young women globally. Consequently, there is a need to analyse this further within countries to establish pertinent policies to reduce current incidence rates. This includes sub-Saharan African countries where there has been a scarcity of information. Consequently, we sought to establish the nature and sources of poisoning in patients admitted to a leading hospital in Botswana to help develop pertinent future policies for Botswana and surrounding countries. Methods: Retrospectively reviewing the medical records of all patients admitted to Princess Marina Hospital (PMH), which is a leading tertiary hospital in the capital city of Botswana, due to acute poisoning over a six-year period. Results: The records for 408 patients were reviewed. The majority of admissions (58%) were females, and the mean age of patients was 21(±14) years. Most poisoning cases (53%) were intentional. The 15-45 years age group was most likely to intentionally poison themselves compared to other age groups, with females four and half times more likely to intentionally poison themselves compared to males (AOR 4.53, 95% CI: 2.68- 7.89, p < 0.001). Half of the patients were poisoned by medicines followed by household chemicals (22%), with females overall four times more likely to be poisoned by medicines compared to males. The medicine mostly ingested was paracetamol (30%). Failing relationships (57%) were the principal reason for intentional poisoning. Six patients died from poisoning representing a 1.5% mortality rate. Conclusions: The findings suggest in-depth and urgent investigations on intentional poisoning are needed among young women across countries including sub-Saharan African countries to inform future policies on prevention strategies. Further, strategies for poisoning prevention should target social and family relationship problems. We will be following this up in the future

Occurrences of Cadmium, Arsenic, Lead, and Mercury in Potable Water in Greater Gaborone, Botswana: Implications for Public Health

Heavy metals, such as cadmium (Cd), arsenic (As), lead (Pb), and mercury (Hg), are often detected in water, causing detrimental effects to human health. This study assessed Cd, As, Pb, and Hg concentrations in drinking water from the greater Gaborone water distribution system supply area. The Inductively Coupled Plasma—Mass spectrometry was used to analyze 200 water samples from water treatment reservoirs, the distribution line, households, and bottled water. Heavy metal pollution was calculated using the heavy metal pollution index (HPI). Average heavy metal concentrations were in the order of Pb > Hg > As > Cd in the overall study, with lead exceeding the permissible limit set by the United States Environmental Protection Agency (US-EPA) in all the samples. Average lead concentrations from indoor taps were 15 times more than untreated raw water. HPI values were respectively 33.2 and 0.74 for the World Health Organization (WHO) and Botswana Bureau of Standards (BOBS). An increase in heavy metal concentrations post-water treatment suggests inadequate system maintenance and possible contamination of water during the distribution system from copper and lead soldered pipes. Further research on the treatment infrastructure and plumbing activities is suggested

Country report on tobacco advertising and promotion ban - Botswana

Overview of tobacco control activities in Botswana The Government of Botswana has long recognized and accepted the need to sensitize its population to the harmful effects of tobacco. The Primary Health Care approach, adopted in the 1970s in Botswana after the 1978 Alma Ata Declaration emphasized this requirement. However, the theme “Tobacco or Health”, launching the first World No Tobacco Day on 7 April 1988 in Botswana, marked the beginning of an intensive anti-tobacco campaign in the country. Since then, World No Tobacco Day has been held annually on 31 May. The commemoration of World No-Tobacco Days together with other educational programmes aimed at different sectors of the population and the general public, have contributed to sensitizing the general public about tobacco products’ harmful effects on human health and fostered a positive political climate. This has led to the development of a comprehensive tobacco control programme in Botswana

The prevalence of oral conditions and tobacco use among dental patients at princess Marina Mental Clinic, Botswana

Background Several studies have associated smoking with oral conditions such as tooth staining and bad breath, periodontal diseases, impaired healing of wounds, precancer and oral cancer. These effects are often visible and potentially reversible after cessation of smoking. Dentists are frequently in contact with the general population and therefore provide an opportunity for early intervention in smoking cessation counseling compared to other health professionals. This study profiled patients with oral conditions, to assess their knowledge on oral conditions and tobacco use. Methods A cross-sectional survey was carried out at Princess Marina Dental Clinic in Gaborone. The study population included all dental patients visiting the clinic. Only dental patients from the age of 18 years old and above participated in the study. Patients were interviewed using a structured questionnaire and investigated clinically for the presence of oral conditions by a qualified dentist. Results The prevalence of Tobacco use was 21% among the patients. The prevalence was significantly higher among patients aged 25 and 36 (p< 0.05). Dental carries was the most common condition affecting 45% of patients followed by periodontal disease affecting 21% of patients. The age group 25-36 years was the most affected by oral conditions (p< 0.05). Current smokers had a higher prevalence of tooth staining (26%) compared with never smokers (11%). Periodontal disease was prevalent in 32% of tobacco users and 20% of past tobacco users. Overall, 25%(n=68) of patients were not aware of the relationship between smoking and oral health. Conclusions Tobacco use prevalence is high among dental patients in this study. The lack of awareness on tobacco use and effects on oral health is also concerning. On account of their frequent contact with the general population, dentists could provide a window of opportunity for early detection of oral conditions associated with smoking, provide patient education, counseling and smoking cessation advice

Risk factors for self-reported carpal tunnel syndrome among hairstylists in Gaborone, Botswana

ObjectivesHairstylists form an occupational group whose tasks involve repetitive and forced movements of hands and wrists, thus posing a risk of developing carpal tunnel syndrome (CTS). This study assessed the prevalence of and factors associated with CTS symptoms among hairstylists in Gaborone, Botswana.Material and MethodsA cross-sectional study was conducted using a self-administered questionnaire distributed among randomly selected hairstylists. The questionnaire gathered information on demographic characteristics, lifestyle, work-related characteristics and psychosocial factors. The Boston Carpal Tunnel Syndrome Questionnaire was used to determine the severity of CTS symptoms and its functional effects. Data were then analyzed using χ2 and logistic regression models. The level of significance was determined at p < 0.05.ResultsA total of 165 hairstylists took part in the study, with 92 (56%) of the respondents being females. The mean age (M±SD) of the respondents was 35.05±7.54 years with an age range of 22–63 years. Seventy-three (42.2%) hairstylists reported CTS symptoms, with the majority (73%) being females. Out of all the CTS cases, 53 (72.6%) and 16 (21.9%) had mild and moderate symptoms, respectively. Over 80% of the hairstylists did not know about CTS. Among individual factors, CTS symptoms were associated with being female (the odds ratio [OR] of 9.99, and the 95% confidence interval [CI]: 3.64–27.44), increasing age (OR 9.84, 95% CI: 2.74–35.36), the length of employment (OR 3.73, 95% CI: 1.39–9.95), hair washing (OR 2.88, 95% CI: 1.41–5.85), an awkward posture (OR 2.52, 95% CI: 1.03–6.19), and the use of a great muscular effort when performing a task (OR 2.39, 95% CI: 1.01–5.72). Perceived heavy workload and stressful work were also risk factors.ConclusionsThe results suggest a high prevalence of CTS among female hairstylists in Gaborone, and also point out that individual, work-related and psychosocial factors are associated with this syndrome. Future large-scale research is needed to establish the extent of CTS countrywide to influence policy-making. Currently, CTS is not listed amongst occupational health diseases in Botswana

The theory of planned behavior as a behavior change model for tobacco control strategies among adolescents in Botswana.

BACKGROUND:Behavioral intentions (motivational factors), attitudes, subjective norm (social pressures), and perceived behavioral control promote or discourage smoking behavior among adolescents. OBJECTIVE:To assess students' behavioral intentions, attitudes, subjective norms and perceived behavioral control on smoking using the Theory of Planned Behavior. The prevalence of smoking among the adolescents is also calculated. METHODS:In this cross-sectional study, structured self-administered questionnaires were used to collect data from adolescents in primary and secondary schools. Data on demographics, behavioral intentions, attitudes, subjective norms, and perceived behavioral control towards smoking were collected. Pearson product moment correlations and logistic regression models were used to determine factors associated with current smoking. RESULTS:A total sample of 2554 (mean age = 15; Range = 12-18 years) students participated in the study. Twenty-nine percent (n = 728) of the students had tried smoking at least once. Smoking was predicted by attitudes, subjective norms, perceived behavioral control and intention.There was a strong association between having a parent or guardian, caregiver or close friend who smoked (p < 0.001) and being a smoker. The majority of students (57%) conveyed that adults talked to them about the harmful effects of cigarette smoking and 50% had discussed smoking concerns with their friends. Students who had positive attitudes towards smoking like "smoking makes you confident" were more likely to be current smokers (OR: 1.63, 95% CI: 1.03-2.59). The feeling or conviction that they could refuse a cigarette if offered was an impediment from smoking (OR: 0.18, 95% CI: 0.13-0.26). CONCLUSIONS:Attitudes, subjective norms, and perceived behavioral control contributed significantly to the students' smoking. Right attitudes must be cultivated and behavioral control must be strengthened for early effective interventions to curtail smoking among adolescents