IT used to be a dirty oul’ town; but now Dublin is a very loud one too. The health of people living in the city centre is even being put at risk, such is the level of noise being created by traffic.

A study by Trinity College Dublin and University College Dublin found 90% of city centre residents have to endure night-time sound levels in excess of those recommended as safe by the World Health Organisation.

It also found 54% of workers and 28% of those living in the city are exposed to daytime noise that could do damage.

The problem is so bad in areas like Tara Street, Pearse Street, D’Olier Street and College Street that researchers recommend the city council consider diverting night-time traffic.

According to the WHO, exposure to night-time noise greater than an average of 45 decibels can produce psychological and physiological symptoms and affect performance. The study, by UCD’s planning department and engineers at Trinity, found 4,600 out of 5,000 residents within one kilometre of Trinity College were exposed to levels greater than this.

More than 27,000 of 48,000 workers in the area were exposed to averages above the 70 decibel guideline for daytime hours, as were 1,400 of the 5,000 residents. After taking noise measurements 24 hours a day for six months, the researchers said the impact of such levels on individuals’ health and quality of life was “likely to be considerable”.

They added the area they surveyed was typical of others.

Enda Murphy, a lecturer in planning in UCD and one of the study’s authors, said: “Because of the impact noise has on sleep disturbance there are secondary effects. After a night being exposed to excessive noise, for example, someone goes into work next day feeling lethargic, with reduced productivity.”

Other studies have found a link between annoyance caused by road-traffic noise and heart disease in middle-aged men, and cognitive impairment in children such as reduced attention span.

Workers and residents near Trinity say they find the noise unbearable. The World Travel Centre offices on Pearse Street is in one of the noisiest areas examined. “The noise level would always be high,” said employee Jane Reddin. “If a window is opened you can hardly hear yourself think.”

Therese Grace, 20, moved into an apartment in Goldsmith Hall, one of Trinity’s student residences, last week and already the noise from traffic on Pearse Street disrupts her sleep. “Even trying to get to sleep is hard,” said the third-year economics and politics student. “I think I’ll just go to the library to study as I feel the noise would disrupt me.”

The study found simple interventions can reduce noise levels. “What we found was if you put traffic restrictions in place along certain routes during night-time, it has a positive effect,” said Murphy.

Dublin’s local authorities recently produced a draft noise action plan. A completed version has to be sent to the Environmental Protection Agency by the end of this month.

Brian McManus, head of Dublin city council’s traffic noise and air quality unit, said: “If any major developments happen in areas that the noise maps show have relatively high sound levels, the developers are going to have to indicate how they will protect people.”

The council is considering a plan to redirect traffic at night.

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