## 4 Discussion  
Previously, montmorillonite clays have been shown to be safe for human and animal consumption based on numerous animal models and human intervention studies in Africa and the United States. However, these parent clays showed a preference for the adsorption of aflat and positively charged chemicals. To develop broad-acting sorbents that can reduce exposures to diverse mixtures of environmental chemicals, we have treated montmorillonite with acid to increase their surface area and porosity, resulting in more active sites for toxin sequestration and binding. The safety of broad-acting APMs and their increased efficacy for aflat, zeanelenone, glyphosate, and PCBs have been previously described [24; 25]. This study was designed to investigate the binding efficacy of APMs for widely used and highly toxic pesticides (individuals and mixtures) with different structural morphologies and modes of toxic action. Based on our results, acid treatment was shown to significantly decrease expansibility in water (\(p\leq 0.01\)), increase surface area by almost 50% compared to the parent clay, and decrease the concentration of trace metals, including framework aluminum, and interlayer calcium and sodium. This has been shown to enhance mesoporous and toxin-binding activity in APMs [43; 44; 45]. Our results are in alignment with Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) reports on the acid treatment of clays [27; 46]. The lead level in APMs showed that lead concentration was not changed by sulfuric acid treatment for 24 h at high temperature. This result suggests that lead is very tightly bound within the clay structure, and cannot be significantly dissociated, even in extreme conditions such as heat and strong acid treatment for long durations. Importantly, these results suggest that lead should not be significantly bioavailable from this clay following ingestion by humans and animals. This conclusion is further supported by our earlier animal  
Figure 8: Hydra toxicity from a pesticide mixture (2 ppm/pesticide) and protection by (**a**) APCM and (**b**) APSM versus parent montmorillonite clays with an inclusion of 0.05% sorbent. Hydra media with 2% APMs and toxin controls are included for comparison. APM sorbents significantly protected against the pesticide mixture with 60–67% protection at the end point (92 h). CM and SM showed limited protection (10%) at the same inclusion rate (\({}^{*}p\leq 0.05\), \({}^{**}p\leq 0.01\)). increase surface area and reduce trace metals. Adsorption isotherms suggest that APMs were able to bind highly toxic pesticides with high binding capacity, affinity and tightness of sorption compared to parent clays. APMs especially enhanced the binding for neutral and negative pesticides and may be mixed with parent montmorillonite to facilitate the binding of positive substances (like paraquat). This is the first report of a sorbent material (other than activated carbon) with high binding efficacy for diverse pesticides. The in vivo hydra assay showed that APMs were safe for hydra at 2% inclusion rate, and its inclusion at 0.05% resulted in a significant protection of hydra against a toxic mixture of pesticides. It is possible that these, and other acid processed clays, may be broad-acting in their ability to decrease exposures to other pesticides and hazardous environmental contaminants. We anticipate the short-term inclusion of broad-acting APMs in the diet of humans and animals as a protective measure to decrease unintended exposures from contaminated food and water supplies at the site of disasters such as hurricanes, floods, chemical spills, fires, and acts of terror. Conceptualization, T.D.P. ; methodology, M.W. ; software, M.W. ; validation, M.W. and T.D.P. ; formal analysis, M.W. ; investigation, M.W. ; resources, T.D.P. ; data curation, M.W. ; writing--original draft preparation, M.W. ; writing--review and editing, T.D.P. ; supervision, T.D.P. ; project administration, T.D.P. ; funding acquisition, T.D.P.