Last week in Pittsburgh, President Trump's Environmental Protection Agency held a public hearing on its proposal to eviscerate yet another set of environmental protections, this time in the form of gas-mileage standards for cars and SUVs. These requirements have helped make America's passenger vehicles more efficient, saving money at the pump. They have also helped to spur innovation and create jobs. But most importantly, these standards have helped reduce pollution that impacts Pennsylvanian's health. By gutting the standards, the Trump administration is once again siding with polluters over the health of children and families in Pennsylvania.

The transportation sector accounts for more than 55 percent of total nitrogen oxides (NOx) emissions in the United States. When NOx and volatile organic compounds combine in the presence of sunlight, ground-level ozone is formed. Breathing ozone can create a variety of health problems, especially for children, the elderly, and those with lung diseases, such as asthma. Breathing ozone can cause chest pain, coughing, and throat irritation, and can reduce lung function and harm lung tissue.  It can worsen bronchitis, asthma, and emphysema, and make the lungs more susceptible to infection.

The statistics on this subject are staggering. According to the Pennsylvania Department of Health's 2015 Asthma Prevalence Report, in their lifetime, one out of every nine adult Pennsylvanians has been diagnosed with asthma. In 2010, the total costs of asthma were estimated to be $181 million and are projected to be $2.6 billion by 2020 across the state.  There are also estimated to be 382,146 children in Pennsylvania with lifetime asthma and one out of every eight women with asthma.

Every day the Department of Environmental Protection and the Wolf administration work to protect Pennsylvanians from dangerous air pollution from stationary sources, such as power plants. However, the largest source of this pollution comes from our transportation sector: cars, trucks, and other vehicles that spew air pollution into the environment.

The federal fuel efficiency and greenhouse gas standards combined with the ability of states to choose federal or California clean car standards have a proven track record of helping reduce air pollution and protect public health, as well as delivering other important benefits.

These standards were negotiated by the federal government, the California Air Resources Board, and automakers in 2012 to make America's cars more efficient and less polluting, and to ensure the ability of America's automakers to succeed in the 21st century, where saving money at the pump and reducing pollution have become important factors for consumers.

This policy has been successful. Thanks to clean car standards, the 2018 Ford F-150 gets better gas mileage than a 2010 Taurus. Federal fuel efficiency standards have already saved Pennsylvanians an estimated $1.2 billion at the pump. At the current pace, this means that the nation's fuel efficiency standards are expected to save the average Pennsylvania household $1,650 in gasoline by 2030 and save the amount of gasoline that would be equivalent to filling 14,072 Olympic-sized pools.

But the benefits go beyond our pocketbooks. Fuel efficiency and greenhouse gas standards are expected to spur growth in the auto industry as it taps into new research and technologies. Overall, these standards are expected to create more than 26,000 new jobs in Pennsylvania alone by 2030.

Pennsylvania and a dozen other states have led the way toward a cleaner, more sustainable future of transportation in America through the adoption of the coordinated federal and California clean vehicle standards, made possible by the Clean Air Act. In Pennsylvania, the Clean Vehicles Program requires all vehicles built in 2008 and later to meet California Air Resources Board certification. These standards would save Pennsylvanians $4.1 billion per year in 2030 and avoid 87.9 million metric tons of carbon dioxide emissions.

But now the Trump administration is proposing to modify the Clean Air Act to remove California's ability to set vehicle standards. We can't let the Trump administration take away Pennsylvania's ability to use standards that help protect the air we breathe and the environment we cherish.

Patrick McDonnell is secretary of the Pennsylvania Department of Environmental Protection.