It’s too bright in Mumbai. And that can make you ill

Light pollution has effects similar to noise pollution on human, plant and animal health, including hormonal changes, sleep disturbance and irritability

mumbai Updated: Dec 15, 2017 09:35 IST
Badri Chatterjee
Badri Chatterjee
Hindustan Times
Activist Sumaira Abdulali with lux meter at Juhu beach.(HT)

In a first, a city-based non-government organisation (NGO) used lux meter – a portable device used to measure light in lux -- to record ambient light levels along Juhu beach, a spot where the civic body installed light emitting diodes (LED) lights in October. The findings? The lux level directly underneath the light is way past the safe limit, according to doctors.

Light pollution is a little known pollutant with effects similar to noise pollution on human, plant and animal health, including hormonal changes, sleep disturbance, irritability among others.

According to the report submitted by NGO Awaaz Foundation to the state environment department and Brihanmumbai Municipal Corporation (BMC) on Thursday, the lux level underneath the lights that are at a height of 100ft through the landward side of the beach was 67,000, while near the edge of the water was 0.03 lux.

Doctors from KEM Hospital in Parel said 20 lux is appropriate for reading; the human eye should not be exposed directly to lux levels exceeding 50-60.

Last month, Awaaz Foundation compiled studies, which point to various sources of light affecting the city. “While the reading towards the landward side is equivalent to direct sunlight at midday, the reading near the edge is equivalent to a moonlit night,” said Sumaira Abdulali, convener, Awaaz Foundation, who recorded light levels around 7.15pm, earlier this week. “The high intensity of LED lighting, next to residential buildings, causes light disturbance and consequent adverse health effects on residents of the buildings. It also blocks natural views of stars and the moon.”

While there are no safety standards for light pollution or a policy to consider its harmful effects, the report urged the state to consider framing a policy to regulate light pollution from various sources such as street lights, private security lights, hoardings and beautification projects.

“There is a need for uniform lighting of lower intensity to make it safe and comfortable for passers-by. It is dangerous if a patch of bright light is followed by dark zones. Many international cities have specific policies to ensure lux levels are not very high, and the night sky is visible. Mumbai needs one too,” said Abdulali.

Dr Arjun Ahuja, head of ophthalmology department, KEM hospital, Parel, said the already existing fluorescent streetlights range emit 50,000-55,000 lux, while the LED lights along Marine Drive give out a maximum of 60,000 lux. “LED lights are not good for the eyes. Both readings noted by the NGO are dangerous -- 67,000 lux is too bright, 0.03 is too dim. The sudden difference between the two can lead to macular retinal degeneration - deterioration of the central portion of the retina. Repeated exposure to such bright light over due course of time leads to lens within the eyes to get burnt and may even lead to cataract,” he said.

According to Ahuja, exposure to such high lux levels can alter a person’s mood and affect metabolism. “These are microscopic changes that we cannot analyse or understand on a daily basis,” said Dr Ahuja. “While we are economising on electricity by shifting to low voltage and more brightness, we are not considering the health effects of reducing the wavelength and increasing the intensity.”

BMC officials said before any commercial lighting project in the city, a detailed discussion with power distributors is mandatory to ensure safety of citizens is not compromised. “The safety related to amount of light emitted by these changeable street lights and impact on health of citizens were discussed before the project was executed,” said Nitin Aarte, executive engineer, BMC mechanical and electrical department, responsible for the Juhu project, adding the intensity was chosen to ensure people’s safety.

“Such lighting projects focus on improving security and increasing the aesthetic beauty of beaches and waterfronts. The coastal authorities have given all clearances, only after considering all environmental concerns. When lights are not installed, the state and civic authorities are blamed for not increasing security, but when it is done, we get blamed for light pollution,” said a senior official from the state government.

First Published: Dec 14, 2017 23:39 IST