A BBC investigation reveals Southampton docks does not monitor its air pollution rates, despite the city being among the most polluted in the UK.
Southampton City Council estimates the port contributes up to 23 per cent of air pollution in the city.
Ships can use a "plug-in" system to reduce emissions but not in the UK.
It comes after the World Health Organisation (WHO) called Southampton one of the most polluted cities in the UK.
The city's port welcomes thousands of ships a year, including some of the biggest cruise liners and container ships in the world.
The vessels leave their engines running while docked to power their electrics, but elsewhere in the world ships use a shore-based electricity supply, virtually eliminating their emissions.
Cargo and cruise ships, including the Queen Mary 2 and Britannia which regularly dock in Southampton, use the method - just not when visiting the British port.
Port Director Alastair Welch from ABP said: "The challenge has been in particular there is no one standard for shore power. I'd like it in place as soon as possible.
"I should emphasise shore power is not the only answer and that's why we're working with solar power and hybrid ships now, because all of them have a part to play for the future."
A review of Air Quality in Southampton in 2015 by the local authority showed the port is believed to contribute between seven and 23 per cent of the air pollution, while cars contribute 18 per cent and HGVs 12 per cent.
The government has since told Southampton to implement clean air zones by 2020 and the council is implementing a Clean Air Strategy to meet national goals.

Andrew Nay, 39, crashed his Land Rover into the girls' family car as he made a right turn across oncoming traffic on the A509 near Wellingborough.
Katrina Raiba, now six, and her sister Karlina, eight, were left paralysed from the waist down.
The girls' parents said they would "never be able to forgive" Nay.
Live: Reaction to sentencing of Andrew Nay
Northampton Crown Court was told Nay, a Jaguar Land Rover manager and off-road driving instructor, was tailgating and "bullying" a woman who had been driving a Mazda.
To get away from him during his pursuit in October last year, she safely turned right onto the B547 towards Little Harrowden.
Nay, who was seen laughing with his male passenger, undertook a Mercedes and then, in an attempt to follow the Mazda, made an "absolutely ridiculous" turn, the court heard.
He hit the family's Vauxhall Signum that was travelling along the A509 in the opposite direction.
The girls' parents, Roberts Raibais and Renate Raiba, released a statement saying: "Andrew Nay's reckless actions had devastating consequences for our two beautiful daughters.
"Katrina and Karlina were happy, active children and he has robbed them of that.  We will never be able to forgive him.
"Every day they ask 'when will we start feeling our legs again?' They think it's going to get better and it's too hard to tell them."
Nay, from Weldon, Corby, admitted four counts of causing serious injury by dangerous driving, but denied he had been chasing the Mazda prior to the crash.
Judge Adrienne Lucking QC said: "This was a prolonged, persistent and deliberate course of very bad driving.
"No sentence I can pass will ever feel like enough for this family."
The judge told Nay his account of events had been "incredible and inconsistent".
Sgt Tony Hopkins, of the Serious Collision Investigation Unit in Northamptonshire, said: "This is probably one of the most tragic cases that I think I've had to deal with in my career to date.
"There is no end for the family, this will go on for years and this will affect them for years."
He added: "I'm pleased to see that the judge has been able to see through Mr Nay's story, and has been able to see what the witnesses have evidenced to us over the few months, to highlight how long this incident actually went on for."
Jaguar Land Rover' said in a statement: "We are deeply saddened by this terrible incident and our thoughts are with the Raiba family. We can confirm that Andrew Nay is no longer an employee of Jaguar Land Rover."
Southampton, the biggest cruise port in Britain, has no way of monitoring air pollution generated by emissions from the largest ships in the world.
[NEXT_CONCEPT]
A driving instructor who left two young sisters paralysed after a "road rage" crash in Northamptonshire has been jailed for four-and-a-half years.