Opposition MSPs pressed the minister on how the zones - which will operate in Glasgow, Edinburgh, Aberdeen and Dundee - will be designed and what type of vehicles will be affected.
They also wanted to know if automatic number plate recognition would be used to track down drivers of more-polluting vehicles and how the schemes would be paid for.
The Scottish Government has already pledged the first LEZ will be established in Glasgow by the end of 2018, with the other three to follow by 2020.
Mr Yousaf said: “Despite making considerable progress, air pollution remains a significant public health and social justice issue.
“With the introduction of low emission zones we are adopting an approach which will help us deliver improvements in air quality and public health.”
Tory transport spokesman Jamie Greene said there was nothing in the minister’s statement that MSPs did not already know.
The Conservative told Mr Yousaf he was concerned about the “distinct lack of detail in the plans” and the “unrealistic” timetable for LEZs - pointing out that 2018 is just 24 days away.
Mr Greene said: “There remain straightforward and substantial questions that need to be answered. What types of vehicles will be affected by the new access restrictions? When will these vehicles be restricted from entering our cities? Will we end up with confusing and differential schemes in different cities? What type of infrastructure will need to be in place when it goes live, and how long will that take to build? How much will it cost and who is going to pay for it?” He added that thousands of motorists were “worried about the potential of being barred from driving to and from their own doorsteps” as he called on Mr Yousaf to “answer some basic questions”.
Labour’s David Stewart also pressed the transport minister on the details of LEZs.