Sir, – The United States Ambassador to Ireland Edward S Walsh has made pertinent observations on the state of Dublin’s neighbourhoods and streets. One factor being ignored in the debate is who creates the filth.Sanitary authorities have a statutory duty to keep public areas hygienic and safe to use. But why are municipal resources focused almost entirely on rubbish removal and not on enforcement of the litter laws?The cigarette butt, plastic bottle, beer can and takeaway box do not appear on the pavement by magic. They are dropped there by humans. And they are rewarded by a 24/7 campaign of collection and deep cleaning at the expense of the taxpayers.Perhaps Dublin City management should sign an executive order bestowing litter act penalty powers on all cleansing staff for a trial period?The stroke of a pen confirming the appropriate financial penalty on the offender may be way more powerful than the sweeping brush. – Yours, etc,LARRY DUNNE,Rosslare Harbour, Co Wexford.