Huge amounts of plastic waste are dumped in the environment and microplastics now contaminate the entire planet, from the summit of Mount Everest to the deepest oceans.

The presence of widespread lateritic formations has been thought to indicate very high rates of silica removal in tropical environments, G.V. Bogomolov et al. (1966) asserting that the silica content of tropical river-waters is greater than that of open streams in higher latitudes, and N.M. Strakhov (1967) noting that the migrational capacity of SiO₂ is particularly high in the humid tropics.

Gradually they reerode and need to be replaced from time to time.

So as not to impede navigation the two principal spans of the bridge were designed to provide a clear headway of 157 ft. above high water for a distance of 500 ft.; ….