Prevalence and determinants of lymphedema in newly diagnosed Nigerian breast cancer patients using bioimpedance estimations.

Background: Breast cancer-related lymphedema (BCRL) is common and has significant impact on quality of life. Very little is known about BCRL in sub-Saharan Africa. Generally, BCRL has been mostly evaluated post treatment, with very limited data on the prevalence of pre-treatment BCRL at baseline. This study presents the prevalence and clinical associations of lymphedema among newly diagnosed, treatment-naive breast cancer patients in a Nigerian cohort using bioimpedance estimations. Methods: Consecutively consenting, newly diagnosed, treatment-naive breast cancer patients were assessed for upper limb lymphedema using bioimpedance measurements of the extracellular fluid and the single-frequency bioelectrical impedance analysis value at 5 kHz. Patients were classified as having lymphedema if there was >10% difference in arm measurements or if the ratios of the arm measurements were >3 SD above a normative mean generated from representative controls. Regression analysis was performed to determine clinical variables associated with lymphedema. Results: There were 154 breast cancer patients with a median age of 47 (40.0-56.8) years and a body mass index of 27 (23.5-30.9) kg/m2. The majority (70%) had stage III disease. All measurements were significantly higher in cases than controls. Using various definitions, the prevalence of lymphedema was between 11.7% and 14.3%. Various clinical variables relating to clinical stage were significantly associated with lymphedema. Conclusion: The predominance of locally advanced disease in the Nigerian setting is associated with high pre-treatment lymphedema rates. This may set the stage for higher rates in the post-operative setting. Management of lymphedema should be incorporated into the treatment planning.

Interventions to Reduce Pesticide Exposure from the Agricultural Sector in Africa: A Workshop Report.

Despite the fact that several cases of unsafe pesticide use among farmers in different parts of Africa have been documented, there is limited evidence regarding which specific interventions are effective in reducing pesticide exposure and associated risks to human health and ecology. The overall goal of the African Pesticide Intervention Project (APsent) study is to better understand ongoing research and public health activities related to interventions in Africa through the implementation of suitable target-specific situations or use contexts. A systematic review of the scientific literature on pesticide intervention studies with a focus on Africa was conducted. This was followed by a qualitative survey among stakeholders involved in pesticide research or management in the African region to learn about barriers to and promoters of successful interventions. The project was concluded with an international workshop in November 2021, where a broad range of topics relevant to occupational and environmental health risks were discussed such as acute poisoning, street pesticides, switching to alternatives, or disposal of empty pesticide containers. Key areas of improvement identified were training on pesticide usage techniques, research on the effectiveness of interventions targeted at exposure reduction and/or behavioral changes, awareness raising, implementation of adequate policies, and enforcement of regulations and processes.

Human health risk assessment of dichlorodiphenyltrichloroethane (DDT) and hexachlorocyclohexane (HCH) pesticide residues in fruits and vegetables in Nigeria.

The residues of dichlorodiphenyltrichloroethanes (DDTs) and hexachlorocyclohexanes (HCHs) in forty-eight (48) composite fruit and vegetable samples (carrot, cucumber, tomato, and watermelon) were qualitatively and quantitatively determined using gas chromatography equipped with electron capture detector (GC-ECD). Safety indices such as the estimated average daily intake (EADI), cancer benchmark concentration (CBC), hazard quotient (HQ) and index (HI), and hazard ratio (HR) were also estimated. Results showed the predominance of HCH and its isomers in the fruits and vegetables as compared with the DDTs. The most predominant HCHs in all the fruits was α-HCH with mean concentrations of 2.704 ± 2.488 mg kg-1 (carrot), 1.536 ± 1.036 mg kg-1 (cucumber), 6.814 ± 2.967 mg kg-1 (tomato), and 9.241 ± 2.735 mg kg-1 (watermelon). The analysis showed that the levels of pesticide residues detected in 25 to 100% of the fruit and vegetable samples were above the UK/European Commission Maximum Residue Limits (MRLs). The non-carcinogenic health risk estimates showed that only α-HCH in tomatoes and watermelon had HQ > 1 which indicates the possibility of systemic health risk in children consumers. The carcinogenic health risk showed that only α-HCH and γ-HCH in children and α-HCH in adults had HR > 1 for tomato and watermelon which implies the possibility of carcinogenic health risk from its consumption. It is therefore paramount to institute a policy and regulatory framework for regular monitoring of pesticide residues in fruits and vegetables in Nigeria in order to ensure food safety for consumers and protect human health.

Dietary risk assessment of organochlorine pesticide residues in maize-based complementary breakfast food products in Nigeria.

The study assessed the levels of organochlorine pesticides (OCPs) in eight brands (A-H) of regularly consumed maize-based complementary/breakfast foods in Nigeria. We also evaluated the dietary exposure of infants and young children to the detected OCPs. The OCP residues were quantified using GC-ECD. A total of 10 OCPs residues (ß-HCH, δ- HCH, heptachlor, endosulfan sulfate, aldrin, endrin, dieldrin, p,p'-DDE, p,p'-DDT and methoxychlor) were detected. Total OCPs burden was highest in brands F, D, and G with mean concentrations of 45.98 mg kg-1, 28.54 mg kg-1 and 21.87 mg kg-1, respectively and the lowest burdens in brands H (1.72 mg kg-1) and A (6.61 mg kg-1). Hazard index (HI) for all the age categories were >1 and all the 6 carcinogens (ß-HCH, heptachlor, aldrin, dieldrin, p,p'-DDE, and p,p'-DDT) identified had cancer risk index range of 5.43 × 10-4 to 2.05 × 10-6 which were above acceptable risk. These results indicated the possibility of both systemic and cancer risks to infants and children consumers of the foods. Food brands manufacturers need to carry out regular pesticide residues analysis of raw materials especially maize prior to the production in order to ensure food safety and quality.

Occurrence and Human Health Risk of Dichlorodiphenyltrichloroethane (DDT) and Hexachlorocyclohexane (HCH) Pesticide Residues in Commonly Consumed Vegetables in Southwestern Nigeria.

BACKGROUND: Fluted pumpkin (Telfairia occidentalis) and amaranth (Amaranthus spp.) are common leafy vegetables produced and consumed in southwestern Nigeria. These vegetables attract insect pests which are controlled by pesticides that may have adverse impacts on human health. OBJECTIVES: To determine the levels of dichlorodiphenyltrichloroethane (DDT) and hexachlorocyclohexane (HCH) pesticide residues in the two vegetables and evaluate the potential health risks associated with their consumption. METHODS: The pesticide residue levels were quantitatively and qualitatively determined using a gas chromatograph coupled with electron capture detector. Health risk assessment were performed using estimated average daily intake and hazard indices for two weight categories: children (16.7 kg) and adults (60 kg). RESULTS: The results showed that delta-HCH, DDT and methoxychlor were predominantly detected in the two vegetables from both farms and markets. In amaranth, the mean concentration of methoxychlor, DDT and delta-HCH were 4.590 ± 2.774 mg/kg (dry weight (dw)), 0.757 ± 0.457 mg/kg (dw) and 0.577 ± 0.390 mg/kg (dw), respectively, while fluted pumpkin levels were 6.223 ± 2.489 mg/kg dw (methoxychlor), 0.504 ± 0.056 mg/kg dw (delta-HCH) and 0.486 ± 0.123 mg/kg dw (DDT). The levels of HCH and DDT residues were generally above the United Kingdom/European Commission maximum residue limit. The analysis of health risk estimates for non-carcinogenic risk revealed that for both vegetables, the hazard quotient for p, p' DDT and methoxychlor was >1 for both children and adults. The health risk estimates for carcinogenic risk revealed that hazard indices values were >1 for children for both vegetables and alpha-HCH had a hazard index >1 for adults for amaranth. This means the residue exceeds acceptable standard and present potential risk to consumers of these vegetables. CONCLUSIONS: The results obtained from the present study indicate that consumption of amaranth contaminated with alpha-HCH could pose a carcinogenic risk for adult consumers. The consumption of the two vegetables could pose both non-carcinogenic and carcinogenic health risks to children and adults. Therefore, there is need for strict enforcement of regulations on pesticide usage to minimize human health risks. COMPETING INTERESTS: The authors declare no competing financial interests.

Dietary exposure assessment of organochlorine pesticides in two commonly grown leafy vegetables in South-western Nigeria.

Organochlorine pesticides (OCPs) are persistent pesticides whose usage have been banned or restricted worldwide and the presence of its residues in vegetables could affect its nutritional quality as well cause adverse health effects. This study quantified the OCP residue levels in commonly grown and consumed vegetables and assessed the carcinogenic and non-carcinogenic health risks from the consumption of the contaminated vegetables. The OCP residues levels in the extract from the vegetables were determined using a Gas Chromatograph coupled with Electron Capture Detector (GC-ECD). Health risk estimates were analysed using Estimated Average Daily Intake (EADI), Hazard Index (HI), and Hazard Ratio (HR) for children (16.7 kg) and adults (60 kg) weight categories. The residue analysis indicated that amaranths had the highest mean concentration of endrin aldehyde (2.987 ± 0.391 mg kg-1) and endosulfan sulfate (0.661 ± 0.280 mg kg-1), while in fluted pumpkin, the highest mean concentrations were endrin aldehyde (3.491 ± 0.376 mg kg-1) and endosulfan sulfate (2.775 ± 0.644 mg kg-1). The percentage of the detected OCP residues above Maximum Residue Limits (MRLs) ranged from 25% to 100% for both vegetables. Non-carcinogenic health risk estimates for the children weight category showed that aldrin, dieldrin, endrin, endrin aldehyde, and heptachlor detected in both vegetables had HI > 1. While for adults, only aldrin, dieldrin, endrin, and endrin aldehyde revealed non-carcinogenic effect in both vegetables. Human risk estimations for the carcinogenic health effect for the two vegetables showed that aldrin and dieldrin could pose carcinogenic health risks to adult, while aldrin, dieldrin, heptachlor and heptachlor epoxide could pose carcinogenic health risks to children. The results revealed both non-carcinogenic and carcinogenic health risks for the consumers of the contaminated vegetables from the selected locations in South-western Nigeria.