Mapping of Airborne Particulate Matter Collected Using Two Sensors along US-Mexico Border

Juan P. Flores Sanjit Deb

doi:10.4172/2161-0525.1000206

Abstract

Particulate matter (PM) emissions from various sources can have significant effect on human health and environmental quality especially in the Chihuahuan Desert region along US-Mexico border. The objective of the study was to determine the effect of road dust texture and vehicular speed on airborne PM concentrations from different unpaved rural roads using two sampling techniques (DustTrak R , and Sticky-tape). The surface soil textures of unpaved roads varied from silty clay to loam with less than 4% soil moisture content at the time of PM measurement. Sticky tape method in seven experiment sites showed that PM ranged from 0.529 to 3.054 mg m -3 , and DustTrak R measurements showed that PM 2.5 concentration ranged from 1.11 to 37.1 mg m-3 at 1 m height. An exponential relationship was obtained between PM 2.5 by DustTrak R and vehicle speeds with an average slope of -1.619 mg m -3 s -1 . The concentration of PM measured with the Sticky-tape decreased with increasing height of measurement. Both PM measurement techniques provided a good approximation of PM emissions at different vehicles speeds, unpaved roads and position of the instrument above ground level for a variety of unpaved roads. The low cost sticky tape method has the potential to further determine and abiotic (elemental composition) and biotic (fungus) particles in airborne PM.

Highlights

Dispersion of particulate matter (PM) in the air is common in the Chihuahuan Desert region [1] classified as arid with low precipitation
The analysis examined the effects of experiment site, vehicle speed, and height on dust emission
The PM emissions were quantified at different vehicle speeds and on different unpaved roads characterized by differences in texture and soil water content using two real-time point sampling techniques

Summary

Introduction

Dispersion of particulate matter (PM) in the air is common in the Chihuahuan Desert region [1] classified as arid with low precipitation. The low soil water content exacerbates dust emissions into the atmosphere, which could have an influence on human health, road safety, and soil conservation [3,4]. In the Chihuahuan Desert region, dust storms occur several times annually, mainly between February and April. Vehicular traffic on the unpaved roads and field operations on agricultural farms are reported to disperse large amounts of PM emissions into the air [5]. Low visibility during dust storms has been reported as the cause of some traffic accidents, while dust storms themselves are associated with soil erosion and are cited as the source of certain construction damage. Blowing dust from high winds is reported to promote respiratory illness [6]

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