Levels of Heavy Metals in Some Vegetables and Human Health Risk Assessment in Loumbila Area, Burkina Faso

Contamination by heavy metals of soil, water and agricultural products is currently a major problem of environmental pollution in the world. The consumption of plants contaminated with heavy metals can be the cause of diseases such as cancers, the number of cases of which is only growing. The objective of this study was to determine the concentration of copper (Cu), chromium (Cr), zinc (Zn), lead (Pb), nickel (Ni), and cadmium (Cd) in plants from the vegetable farm of LOUMBILA and the assessment of health risks linked to the consumption of plants. In this paper, the concentration of heavy metal in vegetable was measured using the model AANALYST 200 flame atomic absorption spectrometer from PERKIN ELMER. The level of Zn in the vegetables from Loumbila vegetable farms ranged between 42.95 mg/kg and 78 mg/kg. The concentrations of Zn in the studies vegetables were higher than the permissible levels set by FAO/WHO (20 mg/kg). The concentration Pb in vegetables varied from 1.73 mg/kg to 27.02 mg/kg. All concentrations of Pb in vegetable were higher than the permissible levels set by FAO/WHO (0.3 mg/kg). Daily intake of Ni, Cr and Pb was higher than the MTDI, so consumption of vegetables from Loumbila vegetable farms can lead to health problems related to Ni, Cr and Pb. In vegetables from LOUMBILA, the estimated daily intake decreased in the following order: Zn > Cu > Pb > Ni > Cr. The Hazard index values for carrot, onion, lettuce, green bean and onion leaves were greater than (>) one (1) which indicates that there might be a potential health risk to those consuming these vegetables. The Target Cancer Risk (TCR) analysis also revealed the potential cancer risk induced by Cu, Ni, Zn, Cr and Pb due to the consumption of carrot, onion leaves, onion, lettuce, green bean, and bell pepper because their TCR values were above the threshold.

Water Dynamics under Drip Irrigation to Proper Manage Water Use in Arid Zone

The water resources reduction due to climate changes and also population increase, have contributed to increasing the constraint on water disponibility and accessibility. In the agricultural field, we need moderate soil and water resources management. This work aims to simulate water dynamics in soil under drip irrigation system in arid regions to better manage irrigation water. Simulations are done with soil physical properties of Burkina Faso. We assess maize plant water requirements for the whole growing season. With Hydrus 2D, we simulate water supply in the soil column. We assign atmospheric conditions on the top of the domain, zero flux of water on the lateral sides, and free drainage on the bottom boundary domain. We perform many irrigation events to analyze wetting pattern distribution around the emitter, which allowed us to contain the amount of irrigation water applied, only around the area dominated by roots, and then reduce water losses that roots cannot uptake. According to the different growing stages of the maize crop, we choose proper irrigation duration and frequency, and suggest irrigation schedule for the whole growing season.

Assessment of Heavy Metal Concentration and Evaluation of Health Risk of Some Vegetables Cultivated in Loumbila Farmland, Burkina Faso

Vegetables such as spinach, African eggplant, cabbage, eggplant, okra, chili peppers and tomatoes are found in our everyday foods and are the most important dietary source of nutrient. But, it becomes deleterious to human as well as animals as it accumulates toxic metals in their tissue when grown in contaminated soil. The mostly consumed vegetables like spinach, African eggplant (fruit and leaves), Corchorus olitorius leaf, Amaranthus hybridus leaf, cabbage, eggplant, okra, pepper and tomato were collected from Loumbila market gardening. Heavy metals copper (Cu), nickel (Ni), lead (Pb), chromium (Cr), cadmium (Cd) and zinc (Zn) were measured using atomic absorption spectrophotometer (AAS) model AANALYST 200 from PERKIN ELMER. The results of this study showed that the concentrations of lead (0.49 to 8.59 mg/kg) and zinc (20.73 to 71.29 mg/kg) in spinach, African eggplant (fruit and leaves), Corchorus olitorius leaf, Amaranthus hybridus leaf, cabbage, eggplant, okra, pepper and tomato exceeded the permissible level of FAO and WHO standard. The daily plant metal intake for Cd (0.001 - 0.015 mg/kg), Pb (0.041 - 0.730 mg/kg), and Cu (0.703 - 1.543 mg/kg) is higher than the recommended daily intake of metals but does not exceed the tolerable limit. The calculated values of the health risk indices show high values for Cd, Pb, Zn, Ni and Cu while low values are observed for Cr. Except for Cr, the IRS evaluated for all the studied metals were greater than one (IRS > 1). This implies that exposed populations are susceptible to developing diseases linked to the following metals: Cd, Pb, Zn, Ni and Cu.

Study of Cassava Contraction during Its Convective Drying

During this study, a focus is placed on the physical transformations that cassava undergoes during convective drying. The product continually changes its size, shape, and even its texture and consistency. The more moisture a product loses, the smaller its size. Firstly, the results show that water parameters such as mass or moisture content are reduced according to the drying principle. The dimensions length L, width l and thickness e decrease following a linear trend. The mathematical equations describing them were determined using the Excel office tool. This trend impacts surface and volume parameters, which in turn decrease almost linearly with the water content of the product. Note that the R2 coefficient is not always acceptable, confirming the complexity of the behavior of organic products.