Effects of Wind Direction on VOC Concentrations in Southeast Kansas

Sergio A. Guerra, Dennis D. Lane, Glen A. Marotz, Ray E. Carter, Carrie M. Hohl, Richard W. BaldaufDepartment of Civil, Environmental, and Architectural Engineering, University of Kansas

Introduction

Southeast Kansas supports the highest concentration of hazardous waste burners in the country 3 cement kilns 1 commercial hazardous waste incinerator

U.S. EPA sponsored the Southeast Kansas Health Study to investigate air quality and potential health effects from ambient air in the area (report available at http://www2.kumc.edu/ceoh/skhs/)

This study was a joint effort between the Department of Civil and Environmental Engineering at KU and the KU Medical Center

Scope

The environmental sampling element of the project included the collection of 24-hr VOC samples at selected sites in Southeast Kansas

Effects of spatial and temporal factors on these concentrations were investigated

Wind direction effects are of particular interest

Air Quality Monitoring

Duration of Monitoring - March, 1999 through October, 2000

Sampling Sites in the cities of Chanute, Coffeyville, Fredonia, and Independence

Additional Sites in Sedan, Tyro, Labette County

Sampling Site Design, Sampling and Analysis Protocols According to EPA Guidelines

Sampling Area in Southeast Kansas

Sampling Area in Southeast Kansas

Tyro- Water Tower

Washington School

South Mound

KDHE office

Admin. Building

Airport

Sedan- Power Pole

Radio Tower

South Farm

Elderly care

Longfellow School

Labette Co.-Junction160/169

Eisenhower School

Lincoln School

South Ash Grove

KDHE Site

Labette Co.-Big Hill Lake

East of River

East Kennel

North Ash Grove

CC Ag.. House

BackgroundIndependenceFredoniaChanuteCoffeyville

Source-specific sites

Wichita windrose (1984-1992)

Fredonia

Site Sampling Methods

LaF-2 PM10 MiniVol*

LaF-3** PM10 MiniVol

LaF-5 PM2.5 MiniVol PM10 MiniVol

**Site was discontinued after March, 2000.

Data Collection- Canister with flow controller and programmable

open/close valve

Sample analysis by GC/MS

VOCs analyzed included: Benzene Toluene Xylene isomers Trichloroethene Tetracholoethene Chloroform 1,1,1-

trichloroethene

Data Analysis

Descriptive statistics were calculated for the VOC concentrations

Data was analyzed for Possible effects of sampling site Possible effects of sampling date

Data Analysis

The temporal factor was further investigated to determine the effect of wind direction on VOC concentrations Data was divided in four wind direction categories (from NCDC);

South North Calm/variable Other

The effect of the targeted sources was also analyzed by using the Wilcoxon signed rank test for the cities of Chanute, Independence and Fredonia

Ambient Air VOC Concentrations Producing Increased Cancer Risks

Increased Cancer Risks VOC Concentration (µg/m3) producing risk levels

1 in 10,000 1 in 100,000 1 in 1,000,000

benzene 13 1.3 0.13

Bromoform* 90 9 0.9

carbon tetrachloride 7 0.7 0.07

Chloroform 4 0.4 0.04

1,2-dibromoethanea 0.5 0.05 0.005

1,2-dichloroethanea 4 0.4 0.04

1,1-dichloroethylenea 2 0.2 0.02

Hexachlorobutadienea 5 0.5 0.05

methylene chloride 200 20 2

1,1,1,2-tetrachloroethanea 10 1 0.1

1,1,2,2-tetrachloroethanea 2 0.2 0.02

Tetrachloroethylene 170 17 1.7

1,1,2-trichloroethanea 6 0.6 0.06

Trichloroethylene 60 6 0.6

* - not detected during this study

Ambient Air VOC Concentrations Producing Other Health Effects

Other Health Effects

VOC Minimum concentration producing health effects (µg/m3)

benzene 60

carbon tetrachloride 40

chlorobenzene 20

chloroethanea 10,000

chloroform 300

chloromethanea 90

dichlorobenzene isomersa 800

1,1-dichloroethanea 500

ethylbenzene 1000

methylene chloride 3000

naphthalene 3

styrene 1000

tetrachloroethylene 300

toluene 400

1,1,1-trichloroethane 1000

trichloroethylene 500

xylene isomers 400

Results

Distribution of VOC Concentrations, 24-hour samples

VOC Number of Samples with Concentration in Each Range

0.1-1.0g/L 1.1-10.0g/L 10.1-100.0g/L >100g/L Health Effectsa

Benzene 54 6 0 0 58

Toluene 40 113 36 6 5

Ethylbenzene 16 56 20 10 2

m,p-xylene 32 42 4 0 0

o-xylene 36 32 0 0 0

Styrene 9 16 17 2 0

Naphthalene 76 46 1 0 14

Chlorobenzene 5 4 0 0 0

methylene chloride 3 26 8 2 31

Chloroform 12 6 0 0 18

carbon tetrachloride 28 2 0 0 30

1,1,1-TCA 7 1 1 0 0

Trichloroethylene 2 12 19 12 44

Tetrachloroethylene 3 16 2 0 14

Isooctane 1 19 7 0 na

VOC observations

Although there are 58 samples with benzene concentrations exceeding the 1-in-1,000,000 level of increased cancer risk, only 5 of those exceeded the 1-in-100,000 level; none exceeded the 1-in-10,000 level.

Other non-halogenated aromatic compounds were detected in a large number of samples, especially toluene, ethylbenzene, and naphthalene. However, only in the case of naphthalene were there more than ten samples with concentrations which could produce health effects.

There were 31 samples with methylene chloride concentrations exceeding the 1-in-1,000,000 level of increased cancer risk. Only eight of those exceeded the 1-in-100,000 level, and only one exceeded the 1-in-10,000 level.

There were 18 samples with chloroform concentrations exceeding the 1-in-1,000,000 level of increased cancer risk, thirteen of which exceeded the 1-in-100,000 level, and two of which exceeded the 1-in-10,000 level.

VOC observations

There were 30 samples with carbon tetrachloride concentrations exceeding the 1-in-1,000,000 level of increased cancer risk, fourteen of which exceeded the 1-in-100,000 level; none exceeded the 1-in-10,000 level of increased risk.

There were 44 samples with trichloroethylene concentrations exceeding the 1-in-1,000,000 level of increased cancer risk. Of those, 38 exceeded the 1-in-100,000 level and 21 exceeded the 1-in-10,000 level.

There were fourteen samples with tetrachloroethylene concentrations exceeding the 1-in-1,000,000 level of increased cancer risk, only one of which the 1-in-100,000 level.

Effects of sampling site

Sampling site was a statistically significant factor for 8 of the 15 VOCs.

Site factor was further analyzed using upwind/downwind sample pairs.

In Chanute and Fredonia, higher concentrations of six VOCs were found in upwind samples. Differences were not statistically significant in Fredonia, but

were in Chanute for toluene, ethylbenzene, and xylene. Results indicate contributions from other sources.

In Independence, significantly higher concentrations of ethylbenzene, styrene, methylene chloride, and trichloroethylene were found in downwind samples. Results indicate contribution from targeted source.

Effects of sampling date

Sampling date was a significant factor for 12 of the 15 VOCs

Wind direction accounted for much of the variation among sampling dates.

Northerly winds frequently produced higher concentrations of benzene and xylene, and occasionally produced higher concentrations of carbon tetrachloride.

Southerly winds frequently produced higher concentrations of toluene, but lower concentrations of naphthalene.

Conclusions Fifteen VOCs were detected above detection limit. Several VOCs were found at concentrations above published risk

levels, although infrequently. Trichloroethylene concentrations were of most concern

44 values exceeded the 1 in 1,000,000 risk level 21 of those exceeded the 1 in 10,000 risk level

Statistical analysis showed that sampling site had a significant effect on the concentrations of many compounds.

Larger than expected highest values were also found at the Coffeyville-KDHE and Chanute-S. Ash Grove sites.

Sampling date was found to be significant for many of the compounds. Wind direction was shown to be a significant factor but not consistently. For example, southerly winds typically produced higher than expected

conc. of toluene but lower than expected conc. of naphthalene.

Conclusions

For four of the compounds, concentrations at sites downwind from the targeted source in Independence were significantly higher than concentrations at upwind sites.

However, in Chanute and Fredonia concentrations were significantly higher at upwind sites.

During the present study several VOCs were found above concentrations that could potentially affect human health, though these levels were infrequent.

It could not be shown conclusively that targeted sources contributed significantly to these concentrations.