A glimpse of the Lehigh Valley from the lookout on South Mountain. Lehigh Valley air quality is the fourth most polluted air in Pennsylvania. (Nik Malhotra/BW Staff)

The tipping point: The Lehigh Valley faces environmental and public health crises


The year 2020 was the warmest year on record.

According to NASA, the concentration of carbon dioxide in the atmosphere has increased by 47 percent since the Industrial Revolution. Earth’s climate has been pushed close to a point of no return, and many scientists believe the tipping point will be reached by 2050. 

Anthropogenic emissions are a leading cause of global warming, in both big cities and small towns. Industry and overpopulation are decimating natural resources critical to sustaining the planet. 

Many look to cities like New York or Los Angeles to blame for more vehicles being put on the road. However, emissions from Northampton County, Pennsylvania, and the greater Lehigh Valley indicate that the climate crisis is also a local problem.

Lehigh University professor Ben Felzer, a climate and biogeochemical modeler, believes public focus should be as much on health as on warming.

“Lehigh Valley air quality is the fourth most polluted air in Pennsylvania, affected largely by diesel traffic,” Felzer said.“Yet, much of the population is unaware of this as a health hazard.”

Felzer spoke to the Sierra Club last year about the effect of diesel engines on air quality.

More vehicles on the road aggravate air quality, consequently creating health problems. In 2018, 82.6 percent of workers commuting from Northampton County drove alone, all contributing to the over 14.5 million vehicle miles traveled per day in the Lehigh Valley. Vehicles release pollutants into the atmosphere and diminish air quality.

Transportation is a primary source of greenhouse gases, accounting for 28 percent of the country’s total emissions in 2018. Northampton County, where the average vehicle ownership is two cars per household, is no exception.

According to the Lehigh Valley Planning Commission, there are approximately 90,000 vehicles per day on Route 22, a major highway running through the Lehigh Valley. These numbers are fluctuating.

“Because of COVID, there’s been far less car traffic on the road,” said Charles Doyle, director of transportation and data management at Lehigh Valley Planning Commission. “Conversely, there’s a growing amount of freight traffic, and it obviously creates more pollution because of these larger vehicles on the road.”

Doyle admits a growing demand for the road is difficult to address. FutureLV is the Lehigh Valley’s 20-year, long-range transportation plan and an outline for the region’s growth. This plan is required by the federal government in exchange for funding for large scale transportation projects. 

More vehicles and diesel engines in Northampton County are contributing to a decrease in air quality as well. Vehicles release toxic pollutants like particulate matter, nitrogen dioxide and carbon monoxide when they burn fuel. 

In its annual report, the American Lung Association gave Northampton County the grade of F on its ozone quality. The grading scale is based on air quality index, a system used to measure if air pollution is dangerous. Ozone is marked as a critical pollutant in Allentown by the Pennsylvania Department of Environmental Protection, showing the importance of the association’s consideration. Northampton County has a small population, approximately 305,000, indicating air quality also affects suburban America.

The Lehigh Valley is one of the biggest hubs for warehouses in the country. More warehouses beget more freight traffic, leading to increased pollution brought on by diesel engines. Fostering the growth of warehousing brings in truck traffic and diminishes farmland. 

Lehigh University professor Breena Holland researches episodic exposure and pollution coming from vehicles in South Bethlehem at different times of the day. Holland and her students use handheld devices to measure black carbon particulate matter.

“What I’m looking at is black carbon particulate pollution, and a very common and known source of that is diesel fuel,” Holland said. “You see significant spikes in the data in the black carbon concentration when a vehicle that is clearly a diesel vehicle passes you on the roadway.”

Holland emphasized the importance of electrifying the entire vehicle fleet. Electrification of the automotive industry is the most immediate way to tackle this issue. 

“It doesn’t need to be done just to deal with the immediate health effects of particulate matter. It needs to be done in order to solve the climate problem,” Holland said of vehicle electrification.

Importantly, the topography of the Lehigh Valley subtly affects emissions in the area, too. 

“The trapping of pollutants is enhanced in the Lehigh Valley due to inversions caused by the topography that prevent air from adequately mixing. So, understanding the local meteorology is crucial,” Felzer said. 

The Lehigh Valley sits between Blue Mountain to the north and South Mountain to the south, creating a dip in elevation that allows air to linger.

Polluted air is proven to cause respiratory illness, heart disease, lung cancer and other maladies. The climate crisis concerns public health as much as the environment.

Primary pollutants emitted by automobiles can be inhaled. Particularly, ozone and particulate matter endanger people’s health. In Northampton County, poor air quality mainly threatens residents with asthma, cardiovascular disease and chronic obstructive pulmonary disease. These residents make up roughly 23 percent of the county’s population, according to the American Lung Association. 

A glimmer of hope is the Pennsylvania government’s gradual commitment to the environment. Pennsylvania spent $710.5 million on environmental and natural resource departments in the 2015 fiscal year. More recently, Pennsylvania has committed to the Regional Greenhouse Gas Initiative, a pledge for 10 New England and Middle Atlantic states to reduce greenhouse gas emissions.

“Addressing the global climate crisis is one of the most important and critical challenges we face,” Gov. Tom Wolfe said in a press release last June. Despite the governor’s affirmation, Pennsylvania remains a leading state in carbon emissions.

The effect of the automotive industry is unmistakable: auto emissions lead to poor air quality and health. With population and infrastructure on the rise, transitioning to sustainable transportation practices is the most immediate way to mitigate air pollution.

Along with the rest of the world, the Lehigh Valley faces the tipping point. 

Will the chaos continue or will there be change? Daily commutes to work are damaging the air, and damaged air is causing illness. Human beings release toxins into the air only to breathe them back in. Everyone is at fault, but nobody wants to take the blame. As emissions go up and traffic never slows down, the Lehigh Valley remains in the middle of an environmental and public health crisis.

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  1. Robert F. Davenport Jr on

    Imagine if Bethlehem Steel was still operating! Rail transit operations reduce emissions but use of them usually requires a change in thinking.

  2. Pakistan, which has an average PM2.5 concentration of 74.27, is the second-most contaminated nation in the world. For most of 2019, AQI levels in Punjab were consistently among the “near unhealthy” or “extremely unhealthy” ratings and even reached as high as 484. Pakistan is experiencing increasing pollution from the increasing number of road vehicles, the loss of trees on a wide scale, smoke from brick kilns and steel mills, and waste burning.

  3. polluted Countries affect the Earth, but it is harmful to humans as well. Air pollution in industry, factories, automobiles, aircraft, and electricity generated by the combustion of fossil fuels causes health issues such as respiratory problems, worsening asthma, and even congenital disabilities. Toxic contamination is among the leading risk factors for non-communicable diseases worldwide, according to Pure Earth. 72% of all deaths are due to non-communicable diseases, 16 percent of which are caused by environmental polluters. 22% of all cardiovascular diseases, 25 percent of stroke deaths, 40% of lung cancer deaths, and 53% of deaths from chronic obstructive pulmonary disease are caused by environmental emissions.

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