An estimated 25,000 households currently live in the area, nearest being 50 metre away the runway.  According to Kathmandu Metropolitan City (KMC), the number of households in the area has doubled in the past 10 years.

The airport manages 194 domestic and 64 international flights, on average, on a daily basis, officials said.

Sarita Rai, administrative officer at the KMC Ward Number 35, said over 20,000 households live in traditional houses without a sound proof mechanism right under the planes’ route. There are over 100 schools, and about a dozen hospitals and polyclinics in the area.

“Teachers have shout at the top of their voice in classes during take-off and landing,” said Nabendra Parajuli, vice-principal at Surbeshwor Lower Secondary School, located just 100 metres from the runway. According to doctors, the noise can cause hearing impairment, hypertension, heart disease, birth defects, stress, annoyance, sleep disturbance and changes in the immune system.

“The vibration produced by aircraft can prove fatal to foetus,” said Dr Jyosthana Tiwari of a birthing centre at Jadibuti. The centre is hardly 150 metre away from the TIA runway. Dipendra Shrestha, deputy general manager at the TIA Improvement Project, argued that the noise pollution was due to limited airport space, geographical structure of the Valley and lack of tree plantation.

The International Civil Aviation Organisation has asked its member states to adopt measures to reduce the number of people affected by aircraft noise. However, the government has not followed the request.

Prakash Adhikari, an aeronautical engineer at the Flight Safety Standard Department, said the TIA has not installed aircraft noise testing equipment as well as the intensity measurement system as most countries have in their international airports. “We cannot say what decibel of sound is produced by aircraft,” he said.