With natural gas and oil prices falling these days amid flagging economic growth, coal-producing firms and ETFs targeting those firms are hurting, as Patriot Coal’s bankruptcy filing earlier this week lays bare, according to an article on Zacks.

In addition, gas is viewed as a cleaner fuel source, further compromising coal’s standing in a world of multiple energy sources. Furthermore, demand for electricity—much of which is generated in coal-fired plants—has slowed as a result of the still-unfolding eurozone fiscal crisis, the Zacks report said.

For investors still seeking coal exposure, the Market Vectors Coal ETF (NYSEArca: KOL) and the PowerShares Global Coal Portfolio (NYSEArca: PKOL) are your best bets, the article said.

For the full story, visit Zacks.com.