Yasekwa ngo-2004, singumvelisi kunye nokuthunyelwa ngaphandle kwezixhobo zemveliso kunye nezincedisi e-China, ezinezigidi ezingamashumi amathathu zeedola ezithengiswa minyaka le kubathengi kumazwe angaphezu kwamashumi amane kunye nemimandla kwihlabathi jikelele.
Sikunikeza ukhetho olungaphezulu kwe-5,000 yeemveliso ezahlukeneyo ezivela kwizixhobo zombane, izixhobo zegadi, izixhobo zepetroli kunye nezixhobo zesandla, onokuthi udibanise kwi-odolo enye kunye nesitya sokuthumela ngokulula.