Heavy metal and bacteria contamination of selected wetland ecosystems on the eastern slope of Mount Cameroon: implications for human and ecosystem health.

The wetland ecosystems on Mount Cameroon's eastern slope, known for their agroecological significance and biodiversity, are facing potential threats such as heavy metal and bacterial contamination due to poor waste management systems and anthropogenic activities. A study was conducted to quantify the heavy metals and bacterial loads in Solanum scabrum Mill., Amaranthus cruentus L.

Beneficial arthropods threatened by synthetic agricultural pesticides around the southeast slopes of Mount Cameroon.

Agriculture is among the main drivers of global biodiversity decline. This research assessed the ecological risk of synthetic pesticides at the southeast slopes of Mount Cameroon on bees and other non-target arthropods (NTAs) using the PRIMET (Pesticide RIsk in the tropics to Man, Environment and Trade) model. Data on pesticide usage (active ingredients, interval, dosage, number of applications), and ecotoxicology (LD and environmental behaviour) were collected from field surveys and the IUPAC databases, respectively, then imported into PRIMET to assess the level of risk expressed in Exposure Toxicity Ratio (ETR).

Heavy metal exposure risk associated with ingestion of Oreochromis niloticus and Coptodon kottae harvested from a lacustrine ecosystem.

Lacustrine ecosystems have not been widely assessed for heavy metal contamination and associated health risks; yet, they could be accumulating these contaminants to the detriment of aquatic organisms and communities relying on them for various aspects. The water quality index (WQI) and concentrations of heavy metals including As, Cd, Co, Cu, Cr, Fe, Mn, Ni, Pb, and Zn in water, sediment, Oreochromis niloticus, and in the endemic and endangered Coptodon kottae in Lake Barombi Kotto in Cameroon were determined to evaluate fish heavy metal bioaccumulation, and heavy metal exposure risk posed to communities consuming these fish species. The WQI of the lake was found to be excellent with heavy metal concentrations that were lower than what was obtained in the sediments and fish samples.

Does pesticide use in agriculture present a risk to the terrestrial biota?

Inadequate pesticide application practices have many implications on human and environmental health. This research aimed at assessing pesticide risks on bees, non-target arthropods (NTAs) and earthworms, using PRIMET (Pesticide Risks in the Tropics to Man, Environment and Trade), a pesticide risk model, in the western highlands agro-ecological zone of Cameroon. For this purpose, information on pesticide usage stratagem (dosage, application interval and number of applications) and ecotoxicological properties (median lethal doses, persistence and no observable effect concentration) were gathered and entered into PRIMET to acquire the Predicted Exposure Concentration (PEC), No Effect Concentration (NEC) and Exposure Toxicity Ratio, ETR = PEC / NEC).