Michael Hart, mũikari wa San Diego, nĩ aathitangĩirwo nĩ kũhĩtũkia mawatho ma thirikari ya Amerika ma kũgirĩrĩria ũhũthĩri wa mĩhũmũ ya rĩera-inĩ. Nĩ ũhĩtanu kũrehe indo cia hydrofluorocarbons (HFCs) hatarĩ na marũa ma mwanya marĩa marekĩtio nĩ EPA (Environmental Protection Agency) Hart nĩ aathitangĩirwo kũgũra indo cia kũhooreria Mexico na gũciingata Amerika na njĩra ya kũmahithĩra rungu rwa tarpaulin na indo cia wĩra.