Russell Leggett and Robert Peach were exposed to lead paint while working to reduce the height of the Nab Tower off the Isle of Wight in the Solent.
The tower was built in the 1920s to detect German U-boats but was never used for the purpose. It has been used as a lighthouse.
Now BAM Nuttall Ltd of Camberley, Surrey, has admitted two breaches of the Health and Safety at Work Act and two of the Management of Health and Safety At Work Regulations at the site.
Four Tees Engineers Ltd of Segensworth admitted breaching the Control of Lead At Work Regulations and failing to ensure the health, safety and welfare of employees.
The breaches happened between March 30 and July 22 last year,.
The court heard Four Tees employees’ work at the tower, which started in March 2013, involved removing steel using industrial torches. Workers from both firms were involved but works were subcontracted by BAM to Four Tees.
BAM did not assess the need for control measures against lead exposure.
The Health And Safety Executive (HSE) said Four Tees overlooked suitable control measures and failed to ensure its employees had appropriate medical surveillance.
Results of blood tests in July last year revealed Mr Leggett’s blood contained 110 microgrammes of lead per decilitre while Mr Peach’s contained 97mcg of lead per decilitre.
The level at which action should be taken is 50mcg per decilitre.
Andrew Moore, prosecuting for the HSE, said: ‘The levels of lead found in the blood of Russell Leggett and Robert Peach were described by a consultant as ‘exceptionally high,’ requiring immediate hospital treatment and specialist advice. ‘
Mr Peach, of Beaulieu Road, Hamble, and Mr Leggett, of Little Oak Road, Southampton, both needed treatment and monitoring before the lead in their blood returned to safe levels after inhaling lead dust and fumes.
They both still work for Four Tees.
Three BAM workers were also exposed but their tests were inconclusive.
The court heard both firms took immediate action after the men’s blood tests.
BAM stopped work at the site, reported the incident to the Health and Safety Executive, and revised its risk assessments.
Restrictions on where workers could drink, smoke and eat were put in place and ‘dirty’ and ‘clean’ areas set up along with a decontamination process.
Keith Morton, representing BAM Nuttall Ltd, and James Buchanan, representing Four Tees, each said the companies apologised to the court and Mr Peach and Mr Leggett. The firms will appear at Portsmouth Crown Court next month.