Occupational exposure to pesticides and neurobehavioral outcomes. Impact of different original and recalled exposure measures on the associations.

BACKGROUND: Several measures of occupational exposure to pesticides have been used to study associations between exposure to pesticides and neurobehavioral outcomes. This study assessed the impact of different exposure measures for glyphosate and mancozeb on the association with neurobehavioral outcomes based on original and recalled self-reported data with 246 smallholder farmers in Uganda. METHODS: The association between the 6 exposure measures and 6 selected neurobehavioral test scores was investigated using linear multivariable regression models. Exposure measures included original exposure measures for the previous year in 2017: (i) application status (yes/no), (ii) number of application days, (iii) average exposure-intensity scores (EIS) of an application and (iv) number of EIS-weighted application days. Two additional measures were collected in 2019: (v) recalled application status and (vi) recalled EIS for the respective periods in 2017. RESULTS: Recalled applicator status and EIS were between 1.2 and 1.4 times more frequent and higher for both pesticides than the original application status and EIS. Adverse associations between the different original measures of exposure to glyphosate and 4 neurobehavioral tests were observed. Glyphosate exposure based on recalled information and all mancozeb exposure measures were not associated with the neurobehavioral outcomes. CONCLUSIONS: The relation between the different original self-reported glyphosate exposure measures and neurobehavioral test scores appeared to be robust. When based on recalled exposure measures, associations observed with the original exposure measures were no longer present. Therefore, future epidemiological studies on self-reported exposure should critically evaluate the potential bias towards the null in observed exposure-response associations.

Self-reported and urinary biomarker-based measures of exposure to glyphosate and mancozeb and sleep problems among smallholder farmers in Uganda.

OBJECTIVE: We aim to showcase the impact of applying eight different self-reported and urinary biomarker-based exposure measures for glyphosate and mancozeb on the association with sleep problems in a study among 253 smallholder farmers in Uganda. METHODS: The questionnaire-based exposure measures included: (1) the number of application days of any pesticide in the last 7 days (never, 1-2; >2 days) and six glyphosate and mancozeb-specific measures: (2) application status over the last 12 months (yes/no), (3) recent application status (never, last 7 days and last 12 months), (4) the number of application days last 12 months, (5) average exposure-intensity scores (EIS) and (6) EIS-weighted number of application days in last 12 months. Based on 384 repeated urinary biomarker concentrations of ethylene thiourea (ETU) and glyphosate from 84 farmers, we also estimated (7) average biomarker concentrations for all 253 farmers. Also in the 84 farmers the measured pre-work and post-work biomarker concentrations were used (8). Multivariable logistic regression models were used to assess the association between the exposure measures and selected Medical Outcomes Study Sleep Scale (MOS-SS) indices (6-item, sleep inadequacy and snoring). RESULTS: We observed positive associations between (1) any pesticide application in the last 7 days with all three MOS-SS indices. Glyphosate application in the last 7 days (3) and mancozeb application in the last 12 months (3) were associated with the 6-item sleep problem index. The estimated average urinary glyphosate concentrations showed an exposure-response association with the 6-item sleep problem index and sleep inadequacy in the same direction as based on self-reported glyphosate application in the last 7 days. In the analysis with the subset of 84 farmers, both measured and modelled post-work urinary glyphosate concentration showed an association with snoring. CONCLUSIONS: Self-reported, estimated average biomarker concentrations and measured urinary biomarker exposure measures of glyphosate and mancozeb showed similar exposure-response associations with sleep outcomes.

Evaluation of two-year recall of self-reported pesticide exposure among Ugandan smallholder farmers.

OBJECTIVES: To evaluate smallholder farmers' recall of pesticide use and exposure determinants over a two-year period in a low-income country context. METHODS: The Pesticide Use in Tropical Settings (PESTROP) study in Uganda consists of 302 smallholder farmers who were interviewed in 2017. In the same season in 2019, these farmers were re-questioned concerning pesticide use (e.g., use of active ingredients) and exposure information (e.g., crops, personal protective equipment [PPE], hygienic behaviours) they had previously provided. The extent of recall bias was assessed by comparing responses at follow-up in 2019 with practices and behaviours reported from the baseline interview in 2017. RESULTS: An 84% (n = 255) follow-up response rate was attained. We found instances of better recall (e.g., overall agreement >70% and Area Under the Curve (AUC) values > 0.7) for the use of some active ingredients, commonly used PPE items, and washing clothes after application, whereas only 13.3% could correctly recall their three major crops. We observed a trend where more individuals reported the use of active ingredients, while fewer reported the use of PPE items, two years later. In general, we found better agreement in the recall of years working with pesticides compared to hours per day or days per week in the field, with no apparent systematic over or under reporting by demographic characteristics. CONCLUSIONS: While some of these findings provide consistency with those from high-income countries, more research is needed on recall in poorly educated agriculture communities in low- and middle-income settings to confirm these results.

Recent pesticide exposure affects sleep: A cross-sectional study among smallholder farmers in Uganda.

BACKGROUND: Poorly educated smallholder farmers in low-income countries are highly exposed to pesticides. This can result in adverse mental health issues, of which sleep problems might be an underlying indicator. We aim to examine the association between sleep problems and pesticide exposure among smallholder farmers in Uganda. METHODS: A cross-sectional survey with 253 smallholder farmers was conducted between October and December 2019. Sleep problems were assessed during the week before the visit using the Medical Outcomes Study Sleep Scale (MOS-SS). Exposure to pesticides was assessed as application days of any pesticide and as use of 2,4-D, glyphosate, mancozeb, organophosphates & carbamates, pyrethroids and other pesticides during the week and year prior to the visit. Associations were assessed using adjusted multivariable logistic regression models. RESULTS: Increased odds ratio (OR) for the sleep problem index 6-items (OR [95% Confidence Interval] 1.99 [1.04; 3.84] and 3.21 [1.33; 7.82]), sleep inadequacy (1.94 [1.04; 3.66] and 2.49 [1.05-6.22]) and snoring (3.17 [1.12; 9.41] and 4.07 [1.04; 15.14]) were observed for farmers who respectively applied pesticides up to two days and three or more days in the past week compared to farmers who did not apply during the past week. Gender-stratified analyses showed a higher OR for female applicators (4.27 [1.76-11.16]) than for male applicators (1.82 [0.91-3.79]) for the association between the sleep problem index 6-items and pesticide use in the week before the visit. Increased ORs were also observed for the association between the sleep problem index 6-item and mancozeb exposure during the past year 2.28 [1.12-4.71] and past week 2.51 [0.86-7.55] and glyphosate exposure during the past week 3.75 [1.24-11.8] compared to non-applicators. DISCUSSION: Our findings suggest an increased risk of sleep problems among smallholder farmers in a pesticide-exposure-dependent way in a low-income context. Further gender-stratified, longitudinal investigations are warranted to confirm these findings.

What agro-input dealers know, sell and say to smallholder farmers about pesticides: a mystery shopping and KAP analysis in Uganda.

BACKGROUND: Pesticides can have negative effects on human and environmental health, especially when not handled as intended. In many countries, agro-input dealers sell pesticides to smallholder farmers and are supposed to provide recommendations on application and handling. This study investigates the role of agro-input dealers in transmitting safety information from chemical manufacturers to smallholder farmers, assesses the safety of their shops, what products they sell, and how agro-input dealers abide by laws and recommendations on best practices for preventing pesticide risk situations. METHODS: Applying a mixed-methods approach, we studied agro-input dealers in Central and Western Uganda. Structured questionnaires were applied to understand agro-input dealers' knowledge, attitude and practices on pesticides (n = 402). Shop layout (n = 392) and sales interaction (n = 236) were assessed through observations. Actual behavior of agro-input dealers when selling pesticides was revealed through mystery shopping with local farmers buying pesticides (n = 94). RESULTS: While 97.0% of agro-input dealers considered advising customers their responsibility, only 26.6% of mystery shoppers received any advice from agro-input dealers when buying pesticides. 53.2% of products purchased were officially recommended. Sales interactions focused mainly on product choice and price. Agro-input dealers showed limited understanding of labels and active ingredients. Moreover, 25.0% of shops were selling repackaged products, while 10.5% sold unmarked or unlabeled products. 90.1% of shops were lacking safety equipment. Pesticides of World Health Organization toxicity class I and II were sold most frequently. Awareness of health effects seemed to be high, although agro-input dealers showed incomplete hygiene practices and were lacking infrastructure. One reason for these findings might be that only 55.7% of agro-input dealers held a certificate of competency on safe handling of pesticides and even fewer (5.7%) were able to provide a government-approved up-to-date license. CONCLUSION: The combination of interviews, mystery shopping and observations proved to be useful, allowing the comparison of stated and actual behavior. While agro-input dealers want to sell pesticides and provide the corresponding risk advice, their customers might receive neither the appropriate product nor sufficient advice on proper handling. In light of the expected increase in pesticide use, affordable, accessible and repeated pesticide training and shop inspections are indispensable.

Precision and accuracy of FEV1 measurements from the Vitalograph copd-6 mini-spirometer in a healthy Ugandan population.

OBJECTIVE: Evaluate the accuracy and precision of the copd-6 mini-spirometer for FEV1 in a rural Ugandan population. METHODS: In a cross-sectional study, 171 smallholder farmers performed spirometry with copd-6, and a diagnostic-quality spirometer. RESULTS AND DISCUSSION: The copd-6 underestimated FEV1 at low flows and overestimated FEV1 at high flows. Across all participants, the device slightly overestimated FEV1 by 0.04 [0.02; 0.06] L. Calibration data showed similar patterns. CONCLUSION: The copd-6 could be considered as an affordable tool for research on lung function impairment in resource-constrained settings. However, further validation in a study population with obstructive lung disease is needed.

Organophosphate and carbamate insecticide exposure is related to lung function change among smallholder farmers: a prospective study.

INTRODUCTION AND AIM: Exposure to some insecticides may cause airway obstruction, but existing evidence is limited by cross-sectional designs and inadequate confounder control. We investigated the relation between organophosphate and carbamate insecticides and pulmonary function in a prospective study accounting for important confounders. METHODS: In a cohort of 364 smallholder farmers in Uganda (69% women), participants underwent pre-bronchodilator spirometry at baseline (September/October 2018) and at two follow-up visits (November/December 2018 and January/February 2019). Exposure to carbamate and organophosphate insecticides was assessed using haemoglobin-adjusted erythrocyte acetylcholinesterase (AChE/Hb). Less than 3% of participants were lost to follow-up. We calculated Z-scores for FEV1, FVC and FEV1/FVC using the Global Lung Function Initiative equations. Data were analysed in linear mixed and fixed effect models accounting for family relationships and repeated measures of exposure and outcome. RESULTS: Low AChE/Hb was significantly associated with low FEV1 Z-score in both unadjusted and adjusted analyses. Compared with individuals with AChE/Hb 25.90 U/g (50th percentile, reference), those with lower AChE/Hb 24.50 U/g (35th percentile) had mean FEV1 Z-score 0.045 (0.003 to 0.087) lower, and persons with higher AChE/Hb 27.30 U/g (65th percentile) had a mean FEV1 Z-score 0.043 (-0.002 to 0.087) higher compared with the reference. Similar, but numerically smaller and statistically non-significant effects were seen for Z-scores of FVC and FEV1/FVC. CONCLUSION: Exposure to organophosphate and carbamate insecticides may lead to lung function decline. Our results add to the growing evidence of health effects in relation to exposure to organophosphate and carbamate insecticides, underlining the importance of minimising exposure.

Prevalence of exclusive breastfeeding among mothers in the informal sector, Kampala Uganda.

Exclusive breastfeeding (EBF) for the first six months of life is effective in preventing infant morbidity and mortality. However, 36% of Ugandan children below 6 months are not breastfed exclusively despite its active promotion. This study determined the prevalence and factors associated with exclusive breastfeeding among mothers working in the informal sector in Kampala district. A community based cross-sectional study targeting 428 interviews with mothers with children aged 0-5 months was conducted. Analysis was done using modified Poisson regression in Stata version 14. The prevalence of exclusive breastfeeding was 42.8%. The factors associated with exclusive breastfeeding included: attending antenatal care at least 4 times (APR = 1.24; 95% CI: 1.01-1.51), intention to exclusively breastfeed for 6 months (APR = 1.26; 95% CI: 1.01-1.57) or longer (APR = 1.38; 95% CI: 1.06-1.76), proper breastfeeding practices (APR = 4.12; 95% CI: 2.88-5.90), age of the infant (APR = 0.78; 95% CI: 0.65-0.94) and (APR = 0.48; 95% CI: 0.39-0.60) for children aged 2-3 and 4-5 months respectively and working in a lower position (APR = 0.68; 95% CI: 0.55-0.83). Mothers should be encouraged to attend antenatal care where they learn about the benefits of exclusive breastfeeding to children below 6 months hence enabling them to make informed decisions about exclusive breastfeeding. The government of Uganda should ensure maternity leave benefits of the employment act are enforced in the informal sector to allow women to practice EBF.

Exposure to cholinesterase inhibiting insecticides and blood glucose level in a population of Ugandan smallholder farmers.

OBJECTIVES: The risk of diabetes mellitus may be elevated among persons exposed to some pesticides, including cholinesterase-inhibiting insecticides (organophosphates and carbamates). The objective of this study was to investigate how acetylcholinesterase activity was associated with mean blood glucose levels among smallholder farmers in Uganda. METHODS: We conducted a short-term follow-up study among 364 smallholder farmers in Uganda. Participants were examined three times from September 2018 to February 2019. At each visit, we measured glycosylated haemoglobin A (HbA1c) as a measure of long-term average blood glucose levels. Exposure to organophosphate and carbamate insecticides was quantified using erythrocyte acetylcholinesterase normalised by haemoglobin (AChE/Hb). For a subgroup of participants, fasting plasma glucose (FPG) was also available. We analysed HbA1c and FPG versus AChE/Hb in linear mixed and fixed effect models adjusting for age, sex, physical activity level, and consumption of fruits and vegetables, alcohol and tobacco. RESULTS: Contrary to our hypothesis, our mixed effect models showed significant correlation between low AChE/Hb and low HbA1c. Adjusted mean HbA1c was 0.74 (95% CI 0.17 to 1.31) mmol/mol lower for subjects with AChE/Hb=24.3 U/g (35th percentile) compared with subjects with AChE/Hb=25.8 U/g (50th percentile). Similar results were demonstrated for FPG. Fixed effect models showed less clear correlations for between-phase changes in AChE/Hb and HbA1c. CONCLUSIONS: Our results do not clearly support a causal link between exposure to cholinesterase-inhibiting insecticides and elevated blood glucose levels (expressed as HbA1c and FPG), but results should be interpreted with caution due to the risk of reverse causality.

Occupational safety and health regulations and implementation challenges in Uganda.

The burden of occupational diseases and injuries is high in developing countries due to several challenges including poor regulatory frameworks. To explore the status of occupational safety and health (OSH) policies and related implementation challenges in Uganda, we reviewed OSH regulations and conducted key informant interviews with stakeholders. We found that the existing OSH laws were largely outdated compared to the current needs of workplaces. Challenges affecting implementation are related to: gaps in the legal framework, low public awareness about OSH, poor planning, and limited human capacity, transparency, and accountability. Measures to address these gaps including training, upgrading OSH laws and policies, and prioritization are warranted to improve the status of OSH in Uganda.

History, evolution and future of environmental health in Uganda.

This article explores the history and evolution of Environmental Health in Uganda under four key themes: training and practice; research; governance, policy and regulatory framework; and challenges. The article also describes the future of the profession. Through a review of documents and key informant interviews, it is noted that Environmental Health in Uganda dates back to colonial times when the country was affected by diseases including plague, trypanosomiasis and small pox. Concerted efforts were advanced to train cadres that would improve the sanitation status and address the prevailing disease burden. Over several decades, the Environmental Health profession has evolved in many areas of training, practice, research and governance, policy and legal framework amidst several challenges. The future of Environmental Health in Uganda will require more advanced training and research, broadened practice, and streamlined governance.

Rate and associated factors of non-retention of mother-baby pairs in HIV care in the elimination of mother-to-child transmission programme, Gulu-Uganda: a cohort study.

BACKGROUND: Poor retention in HIV care of mother-baby pairs remains a public health challenge in the elimination of mother-to-child transmission (eMTCT) of HIV. We determined the rate of non-retention and time to non-retention of mother-baby pairs and associated factors in Gulu district, Northern Uganda. METHODS: Mother-baby pairs enrolled into the eMTCT programme at Gulu Regional Referral Hospital (GRRH) and Lacor Hospital (LH) were retrospectively followed for 18 months. The primary outcomes were the rate of non-retention and time to non-retention of mother-baby pairs in HIV care. Data were abstracted from the antiretroviral treatment and early infant diagnosis (EID) registers, and mother/baby appointment books at the health facilities. Additional data on possible reasons for non-retention were obtained from cross-sectional interviews of mothers. Time to non-retention was calculated as the duration between enrolment of mother-baby pair into care and the date when the mother and/or baby missed a scheduled visit and did not return within 30 days. Factors associated with time to non-retention were assessed using Cox proportional hazards regression analysis. The measures of association were expressed as hazards ratio (HR) with 95% confidence intervals. Alpha was set at 0.05. The adjusted analysis includes variables with p <0.2 in the bivariable analysis or considered potential confounders. The Analysis used Stata version 12. RESULTS: A total of 410 mother-baby pairs were enrolled in this study. Overall, non-retention by 18 month was 30.5%; higher at GRRH (34.7%) than LH (25.8%), p = 0.049. Non-retention was higher among pairs where the infant had no EID, adjusted (adj) HR = 5.81; 95% CI (2.55, 13.24), non-disclosure of mother's HIV status, adj.HR = 1.86; 95% CI (1.22, 2.85), and lack of privacy during counselling session, adj.HR = 1.86; 95% CI (1.26, 2.85). Non-retention was about 60% lower [adj.HR = 0.43; 95% CI (0.20, 0.92)] among pairs where the mothers understood and appreciated the importance of adhering to all clinic appointments together with the baby. CONCLUSION: Nearly a third of mother-baby pairs are not retained in HIV care. Lack of EID services, poor quality service, non-disclosure of mother's HIV status, and understanding the importance of adhering to all appointments together with the baby, were associated with time to non-retention.