Clearing Nepal's dusty skies

Particulate matter (PM10), fine particulate matter (PM2.5), total suspended particles (TSP) and dust are typically released by construction projects during activities like grinding and crushing equipment, batching plant, quarries, road works, exhaust emissions and vehicle movement on unpaved roads, which lifts up dust. Exposure to the smallest particles can lead to breathing difficulty and worsen existing heart and lung conditions. At the same time, deposition of the larger dust particles affects the general quality of life in surrounding communities and causes problems for local businesses.

I found Nepal to be a dusty country even when not travelling through endless roadworks. Baseline air quality monitoring which was undertaken prior to any construction works showed that the Nepal national air quality objectives for PM10, PM2.5 and TSP were already exceeded.

Even though baseline levels of particulate matter were high, residents are still aggrieved by the additional dust created by the construction works, to such an extent that I spotted one resident doing her own dust management near her shop by sprinkling water on the unpaved road next to the property. When asked why she did this she replied that it was to reduce the dust that her customers would be exposed to – she was simply trying to keep her shop going under difficult circumstances.

Dust from the projects is clearly causing annoyance and broader problems. And with higher dust levels now occurring with greater frequency, neighbouring communities are having to live with reduced air quality and more pollution, and have been left to clean up their own environment more than they were previously used to.

We heard how it’s the human right of every Nepali citizen to have access to food. It is written into their constitution. However, the right to clean air is just as important, because the small particles PM10 and PM2.5 which are released into the atmosphere from these construction activities can exacerbate existing lung and heart disease and impact the health of young children and older people.

Angela Goodhand and Mark Broomfield visit the site of the dam construction

The aim of our visit was to establish which dust measures were currently in place as part of the projects, and to advise on better ways to manage dust – including low- or zero-cost measures that can be put in place to reduce dust nuisance and health impacts, and improve quality of life.

During our workshop with representatives from the contractors we highlighted the health and nuisance impacts of both PM and dust, and emphasised the importance of systematic assessment and management of dust to deliver a high standard of control at minimum cost.

It became apparent during our visit that the contractors are implementing several dust management practices, such as water suppression at regular intervals, but the intense use of unmade roads by normal day-to-day road traffic and the quick evaporation of water means there is a limit to the benefit of these measures.

There are also some significant constraints on what they can do given that the project design is already in place and it is too late to implement measures that would ideally have been implemented from the get-go to reduce dust impacts (for example, diversion of traffic only onto paved road).

Nevertheless, we provided the contractors with a resource of over 100 measures to consider which could still be put in place. We also provided several tools to help manage dust levels, including undertaking a dust risk assessment, conducting daily visual assessments, carrying out PM/dust monitoring, checklists of routine measures, and regular forecasting of dust levels.

Where dust is visible on site and/or there is a forecast of higher dust due to more intense activity or adverse weather, we advised that the contractors consider further additional measures which may not be within their current list of options.

In some conditions, such as in extremely heavy winds, ceasing of all site work might be the only effective action. However, given the time constraints - with the projects already experiencing delays and budget constraints - that is a complex option that may not happen any time soon.

However, my hope is that the advice we provided will not only give the roads and dam contractors the tools to improve current practice but also set a much higher benchmark for dust control during future projects in Nepal, especially as the country gears up to undertake even more infrastructure programmes in the future as part of its national development agenda.