I recently had to travel to Phuntsholing. The Gedu-Passakha diversion gave me the chance to pass through our country's most industralised/polluted zone. Think fog/smog could be seen for a strech of about 10 to 15 kms. The pollution is a reason for concern for the Bhutanese and as well as the indians bordering Bhutan.
The logic of the industries in passakha is perhaps worth a thought. It consumes the energy the country could have exported to India. If rumours are to be belived it, the owners of the industries are mostly Indians, so most of the profit goes to India. The employment generation for the Bhutanese from these factories are neligible ( no data to confirm, but i have been told they are mostly Indians). Importantly, the pollution seems huge.
Perhaps, exploring high employment generation aveneues with low electrcity intensity is the right path. The Call Center boom is our neighbouring countries is perhaps the way forward!!