Quantifying source contributions of volatile organic compounds under hydraulic fracking moratorium.

Area of Science:

• Environmental Science
• Atmospheric Chemistry
• Public Health

Background:

• Volatile organic compounds (VOCs) are precursors to ozone and particulate matter, linked to respiratory and cardiovascular issues.
• The shale gas boom and hydraulic fracturing raise public health concerns regarding airborne pollutants.
• Maryland's moratorium on natural gas extraction provided a unique setting to study VOC sources.

Purpose of the Study:

• To identify and quantify sources of VOCs in Maryland during summer and winter.
• To assess the impact of various emission sources on ambient air quality.
• To understand seasonal variations in VOC concentrations and their implications for ozone production.

Main Methods:

• Stationary trailer-based ambient air monitoring was conducted over two periods: summer 2014 and winter 2014-2015.
• Positive matrix factorization (PMF) was used to identify and apportion VOC sources.
• Analysis focused on VOC concentrations, seasonal variations, and their relationship with nitrogen oxides (NOx).

Main Results:

• Ethane was the most abundant VOC, with higher concentrations observed in winter.
• The fugitive and evaporative factor was the dominant VOC source, accounting for 44.5% of total VOCs.
• Motor vehicles were the second largest source (15.5%), indicating significant contributions from both industrial and transportation sectors.
• Oil and gas activities showed a considerable impact on regional VOC abundance.

Conclusions:

• Fugitive and evaporative emissions, including those from oil and gas activities, are major contributors to VOCs in the study region.
• Seasonal variations in VOCs influence ozone production, particularly in NOx-limited environments.
• Understanding VOC sources is crucial for developing effective air quality management strategies to mitigate health impacts.