Houston, like many American cities, has areas with soil contaminated by non-biodegradable and persistent pollutants such as arsenic, lead, nickel and cadmium, known as heavy metals and metalloids.

Do you know the nutrient level of the soil in your garden? Do you know how much fertilizer to add next season? Soil testing ...

were re-analyzed by an ore grade 4-acid digestion single element ICP-ES method (MSA method code ICF-6xx where xx is the element). Pb values >20% were further analyzed by volumetric titration. Soil ...