A report being released today says thousands of Texas school buses emit exhaust harmful to children's health.
The report by the environmental advocacy group Environmental Defense also calls for the state to pay for replacing or upgrading old buses.
School districts across the state operate some 35-thousand buses. More than one-third of those were built before 1994.
Environmental Defense cites the dangers of fine particle pollution produced by older-model diesel buses. The emissions can cause asthma attacks, dizziness and coughing, according to the report.
The group says the project could be done with a 50 (m) million dollar surplus projected for a state emissions reduction fund.
But a spokeswoman for the Texas Commission on Environmental Quality says tapping the fund would require the Legislature's approval.