The writing process for the majority of Metallicaâs albums have followed the same process. A large slew of guitar riffs written primarily by James Hetfield, sometimes Kirk Hammett, and rarely the bandâs bass player, (that now being bass virtuoso Robert Trujillo) are reviewed and selected.
1 Delhi is most polluted city in the world in PM2.5 concentrations. 2  Half of the top 20 most polluted cities were in India, according to data.  PM2.5 is considered most harmful to health.
Worldâs Most Polluted River. Citarum River, Indonesia, has been called the worldâs most polluted river. Around 5 million people live in the riverâs basin, and most of them rely on its flow for their water supply. Citarum River has an important role in the life of the people of West Java, as it is used to support agriculture, water supply, fishery, industry, sewerage, electricity etc.