Mumbai and Delhi are among the 25 dirtiest cities in the world while the four Indian metros and Bangalore are among the 20 densest cities, according to the Forbes magazine.
The US business magazine also lists Sukinda in Orissa and Vapi in Gujarat among the 10 most polluted places globally.
While listing Mumbai as the seventh dirtiest, the magazine also cites a recent private sector proposal, Vision Mumbai, which seeks $1 billion government aid for infrastructure, pollution control and economic growth strategy.
Delhi at No.24 fares little better but gets drubbing for the pollution in Yamuna river, which is devoid of marine life and where "garbage and sewage flow freely, creating a rich environment for the growth of water-borne diseases contributing to extremely high rates of infant morbidity."
In neighbouring Bangladesh, Dhaka, with lead-poisoned air and water pollution from pesticide use, gets the dubious distinction of being the second dirtiest city in the world.
The top slot as the dirtiest city in the world is taken by Baku in Azerbaijan, suffering life-threatening levels of air pollution emitted from oil drilling.
The list, now on the magazine's website, is based on Mercer Human Resource Consulting's ranking of over 200 cities worldwide on levels of air pollution, waste management, water potability, hospital services, medical supplies and the presence of infectious diseases. New York was used as the norm.
In an earlier Forbes list of the 20 densest urban areas in the world, Mumbai and Kolkata occupied the top two slots, packing in over 23,000 people per square kilometre.
India and China combine to claim nine of the 20 slots, according to 2007 statistics from citymayors.com.
Chennai is at No.8, Delhi at No.13 and Bangalore at No.19 in the list of densely populated cities. Karachi in Pakistan is at No.3.
Living in a dense place affects quality of living, unless you have loads of money and the place is gentrified like Tokyo and New York, the magazine commented. Dense is, however, a relative term. "A Mumbai native visiting New York is bound to feel like a New Yorker vacationing on a Wyoming dude ranch," it added.
In Forbes' list of 10 most polluted places on earth, two Indian towns figure. In Sukinda, Orissa, large swathes of the area's surface water and drinking water contain very high covalent chromium levels, potentially affecting 2.6 million people, the magazine said.
Sukinda is home to almost all of the country's chromite ore deposits and one of the largest opencast chromite ore mines in the world.
In Vapi, the pollutants are chemicals and heavy metals from industrial estates, potentially affecting over 70,000 people. Mercury in the groundwater here is reported to be 96 times higher than the World health Organisation (WHO) standards.
Local produce can contain up to 60 times more heavy metals, such as copper, chromium, cadmium and zinc than non-contaminated produce in control groups, Forbes reported.
China and Russia contributed another two cities each to the 10 most polluted places list, prepared by the non-profit Blacksmith Institute.
"In some towns, life expectancy approaches medieval rates, and birth defects are the norm, not the exception," according to the institute. "In others, children's asthma rates are measured above 90 percent and mental retardation is endemic."
Forbes added: "Fast-track economic growth and years of unregulated mining and chemical production have laid waste to the homes of millions."