Table 1 Outline of convergent parallel mixed-method design process

Phase 1-Convergent parallel mixed method

Systematic literature review

1. Review literature on potentially toxic chemicals, health risks, and risk management frameworks

Studies and reports published in English from 2002 to 2022 in peer-reviewed journals

Data following the 4-step PRISMA guidelines

Thematic analysis

Quantitative study

2. To determine levels of heavy metals and cyanide in surface water, soil, and vegetables

Soil, surface water, and vegetable samples

Grab samples to be analysed in a laboratory using FAAS

ANOVA, PCA, and correlation analyses in R Studio

3. To characterise health risks associated with exposure to heavy metals and cyanide in environmental samples

US EPA risk assessment method

USEPA method to be used to characterise health risks

Statistical analysis in R

4. To model data on heavy metals and cyanide levels, and health conditions using the Akaike information criterion (AIC) and the data’s relevance for the framework development

Models will be generated using AIC to determine the best fit for data

Data from environmental samples and health conditions to be collected from the community health survey

Qualitative study

5. To explore community health problems associated with heavy metals and CN contamination

Health practitioners, EMA officers, teachers, residents, and community leaders

Data collected using focus group (FGD), and interview guides

Thematic analysis in NVivo 12 software

6. To assess the legal framework or schemes for the prevention and control of toxic metal/cyanide pollutants in Zimbabwe

Acts of parliament, regulations, and by-laws

Review of statutes on heavy metals and cyanide pollution

Thematic analysis