The RH has a hard surface, small bulk density and high
amorphous silica content (the highest among the Gramineae
plants) . Its final disposal in landfills gives way to a source of
pollution, i.e., eutrophication and perturbations in the aquatic
and terrestrial life. Additionally, its uncontrolled combustion could
cause environmental and accumulative health problems due to the
formation of crystalline silica (quartz and cristobalite) particles,
which remain suspended in the air.