Cement and brick factories in and around Lumbini Province are contributing to elevated nitrogen dioxide (NO₂) pollution levels in Nepal, surpassing even those in the Kathmandu Valley.
A study led by Madhu S. Gyawali used high-resolution satellite data to track air pollution sources. The US-based research team included Gyawali, Lok N. Lamsal, Sujan Neupane, Bimal Gyawali, Keshav Bhattarai, Bradford Fisher, Nickolay Krotkov, Jos van Geffen, Henk Eskes, Shriram Sharma, Cameron Brunt, and Rudra Aryal. The researchers represented institutions such as San Jacinto College, NASA Goddard Space Flight Center, the University of Maryland Baltimore County, the Royal Netherlands Meteorological Institute (KNMI), Tribhuvan University, and Franklin Pierce University, among others.
Rudra Aryal, a professor at Franklin Pierce University, expressed deep concern over the rising pollution levels near Nepal’s brick and cement factories. “We’ve found that air pollution in this region could become fatal if not addressed promptly,” he warned.
The study analyzed NO₂ distribution from 2018 to 2021, focusing on emerging pollution sources from brick and cement factories. “The rapid expansion of these industries has made the Lumbini-Butwal-Palpa corridor more polluted than Kathmandu,” said Aryal. “Cross-border pollution emissions further exacerbate the problem.”
Nitrogen dioxide (NO₂), a key air quality indicator, was monitored using satellite data from the TROPOspheric Monitoring Instrument (TROPOMI). Findings revealed that NO₂ levels in the Lumbini-Butwal-Palpa corridor nearly doubled between 2019 and 2021, while levels in Kathmandu remained stable except for a temporary drop in 2020 due to Covid-19 restrictions.
A comparison between 2018 EDGAR emission data and 2019 TROPOMI estimates showed comparable NOₓ emissions in the Lumbini corridor but 35 percent higher satellite-derived estimates over Kathmandu. This discrepancy, along with surging emissions from cement and brick industries, underscores the urgent need for updated emission inventories, the study notes.
Published in ScienceDirect, the research highlights serious environmental and public health risks from unchecked air pollution.
Nepal has 114 registered cement plants, with 65 currently operational, producing 14 million metric tons annually. Production increased from 0.3 million tons (pre-2010) to 10 million tons (2018), driven by urbanization and infrastructure demands. A third of these plants are concentrated in the Lumbini-Butwal-Palpa corridor, near the UNESCO World Heritage Site of Lumbini. The Hongshi-Shivam Cement plant, operational since 2018, is the largest, producing 6,000 tons daily.
These industries rely on 171 licensed limestone mines, with raw materials transported by hundreds of heavy trucks. Coal imported from South Africa and India is burned at high temperatures (exceeding 1,400°C), releasing significant NOₓ emissions.
Meanwhile, 1,700 brick kilns across Nepal produce 5 billion bricks annually, primarily in the south-central and southeastern regions. Most operate only outside the June-August monsoon season. A 2014 report found that 50 percent of kilns use coal and rice husk, 26 percent use coal with biomass, and 24 percent rely solely on coal, emitting carbon monoxide, NOₓ, and black carbon.
Despite their environmental impact, brick production technology remains outdated and highly polluting. “The government must take immediate action to mitigate these deadly environmental and health hazards,” urged Aryal.
However, Nepal’s Ministry of Forests and Environment admits that beyond drafting policies, little concrete action has been taken to address the crisis.
