Plans to expand a quarry have been refused over fears it would affect children's health at a nearby school.
Hundreds of people in Normanton and Altofts were against the extension of Rudd Quarry, which would move it closer to Altofts Junior School.
MP Yvette Cooper said dust would aggravate the asthma of more than 15 children as well as disrupt lessons because of noise.
The quarry said the expansion was vital to protect builders' jobs.
A letter written by Ms Cooper, read out at Wakefield Council's planning committee, said more than 15 children at the school suffered with asthma as well as another child who has a life-limiting respiratory illness, according to the Local Democracy Reporting Service.
She added: "Noise, dust and the risk to air quality would make it harder for pupils and teachers to concentrate in school during such a vital stage in their development."
Council leader Peter Box, who represents Altofts and Whitwood, had argued against the plans, stating it would have a "devastating impact on the community".
He said: "How can we expect young people to achieve their full potential when they have to put up with constant noise during lessons and polluted air when they come out?"
More than 460 objections, including dozens of letters written by school children, had been received against the plans to expand the brick and clay quarry on to green belt land on Newlands Avenue.
About 50,000 tonnes of material would have been extracted each year for a period of 14 years.
Philip Sherland, on behalf of Braithwaite Excavations which runs the quarry, had said the expansion was needed because there had been an increase in demand for bricklaying materials.
The plans were unanimously turned down by the committee's 12 councillors.