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PUBLIC HEALTH ASSESSMENT

AGRICULTURE STREET LANDFILL
NEW ORLEANS, ORLEANS PARISH, LOUISIANA


SUMMARY

  1. Agriculture Street Landfill (ASL) is a former landfill that has been developed in part for residential use. Site contaminants have been detected in soil, dust, air, and garden produce. Residents may be exposed to site contaminants through ingestion, skin contact, or breathing. The primary contaminants are metals, polycyclic aromatic hydrocarbons (PAHs), volatile organic compounds, and pesticides.

  2. The undeveloped area of the site has been classified as a public health hazard. The highest levels of contaminants have been detected in the undeveloped area. Although access to this area has been restricted by a fence, individuals continue to access this area and may come in contact with the elevated levels of lead and arsenic in the soil. If this area was developed for future residential use, exposure to lead, arsenic , and polycyclic aromatic hydrocarbons in the soil would pose an unacceptable health risk to residents.

  3. The majority of the residential area and the Press Park Community Center have been classified as no apparent public health hazard since the levels of contaminants in the soil are generally below levels of health concern. There are scattered pockets of lead, arsenic, and polycyclic aromatic hydrocarbon contamination that need to be addressed to limit any possibility of exposure at levels of health concern.

  4. The Moton School poses no public health hazard since the levels of contamination in the soil, air, and water were well below levels of health concern.

  5. Blood lead levels of most of the children that live on the site were below levels requiring medical intervention. Indoor dust, tap water, and paint chips are not significantly contributing to the lead exposure of residents of the study group homes.

  6. Citizens are concerned about their health and have reported a number of health problems. Other concerns include: cleanup activities on the developed area, run-off of contaminants from undeveloped area during flooding, maintenance of undeveloped property, and poor response from utility companies.

  7. Based on the data reviewed, it is recommended that measures be taken to limit residents' exposure to areas where soil is contaminated at levels of health concern. Access to the undeveloped area should be restricted. The undeveloped area of the site should not be developed for residential use until adequate measures are taken to reduce contamination in the soil.

INTRODUCTION

The Agriculture Street Landfill (ASL) is a 95 acre site located in New Orleans, Louisiana. The site was used as a municipal landfill receiving municipal waste and construction debris, for more than 50 years prior to being developed for residential and light commercial use (for complete site history and demographics refer to Appendix I). The landfill was closed in 1966. In the early 1980's, Gordon Plaza Subdivision, Housing Authority of New Orleans (HANO) housing, Gordon Plaza Apartments, the Moton School, the Press Park residential area and community center were constructed over the landfill. Forty-eight acres of the landfill remain undeveloped. Metals, pesticides, and polycyclic aromatic hydrocarbons (PAHs) have been found in surface and subsurface soils during environmental studies.

Blood lead screens and a health survey have also been conducted for the Agriculture Street Landfill Community. The information from the environmental and health studies are summarized in this health assessment.

This health assessment will provide information to explain:

  1. the areas where residents may be exposed to site contaminants (residential area, Moton School, Press Park Community Center and the undeveloped areas).

  2. the ways (pathways of exposure) residents may come into contact with site contamination (by ingestion, skin contact, inhalation).

  3. the types and levels of chemicals detected in soil, air, produce, and water.

  4. the health effects of exposure, if any, to chemicals found in the soil, produce, water, and air.

  5. the findings of past health studies.

  6. the concerns expressed by the community.

  7. the need, if any, for follow up health activities based on the findings of the environmental and health studies.

SITE DESCRIPTION

There are 4 areas on the ASL where residents may come in contact with contaminants. These areas include: 1) residential areas (Gordon Plaza Subdivision, Housing Authority of New Orleans (HANO), Gordon Plaza Apartments, 2) Moton Elementary School, 3) Press Park Community Center and 4) the undeveloped area (see figure 1). In the residential area, Gordon Plaza Subdivision consists of single family homes with small front and back yards. There are some gardens and playgrounds in the backyards. The HANO units consist of 2 story brick units. The HANO units have a grass covered common area. The Gordon Plaza Apartments consist of 2 story buildings with apartments for physically-challenged older persons. There is a grass covered common area.

Moton Elementary School was closed on August 26, 1994. The children that once attended this school have been bused to different schools in the surrounding area. Children in the residential areas surrounding the school still play on the school yard, year round. There is grass cover on the playground.

The Press Park Community Center is used as a meeting place for community events. Children use the yard surrounding the center as a playground year round.

The undeveloped area has been fenced with an eight foot high fence since 1993. A number of holes have been found in the fence. There are pathways that indicate that individuals are trespassing onto the undeveloped area. The area is heavily vegetated with trees, shrubs, and grasses. Wildlife, insects, and rodents use the area for nesting. An abandoned structure, the former recycling facility, is located within the fenced area. The future zoning for this area is light industrial and possibly residential.

For a more thorough description of the site, the historical operations, and the demographics, please see Appendix I.


PATHWAYS OF EXPOSURE

Site contaminants have been detected in four types of media to which residents may be exposed. These media include soil (surface and subsurface), groundwater, air, and produce. In order for an individual to be exposed to a contaminant in the soil, air, groundwater, or produce, a pathway must exist for the exposure to occur.

A pathway of exposure consists of five elements: a source of contamination (i.e. contaminants from past landfill operations), transport of the contaminant through an environmental medium (i.e. lead in soil), a point of exposure (i.e. yard, house, undeveloped area or playground), a route of human exposure (eating/drinking, breathing, or skin contact), and an exposed population (residents, trespassers, or workers).

A pathway maybe completed, potential, or eliminated. A completed pathway of exposure is one in which all 5 elements of a pathway are present. A potential pathway of exposure is one in which at least one element of a pathway is missing but is likely to occur. An eliminated pathway is one where one element of a pathway is missing and will never occur. A pathway of exposure may have occurred in the past, may be occurring in the present, or may occur into the future.

A description of the pathways of exposure that can occur at the ASL site are provided below. In the next section (Extent of Contamination and Toxicological Implications of Exposure), we will describe the health effects that are likely to occur from exposure to contaminants in each of these pathways.

Surface Soil: Individuals may be exposed to site contaminants in the soil through ingestion or skin contact with the soil. This could occur during activities such as children playing in their yards or while adults are gardening or doing other outdoor activities. Workers or trespassers may also come in contact with the surface soil on occasion while working or trespassing on the site through ingestion or skin contact. These are considered completed pathways of exposure.

Subsurface soil: Primarily adults, such as workers, may come in contact with contaminants in the subsurface soil through ingestion or skin contact during activities when the soil is being removed (for example, utility work). There may be inhalation exposure to volatile organic compounds that are trapped between the soil particles. These are considered potential pathways of exposure.

Groundwater: Groundwater is not used as a current source of drinking water or irrigation. Drinking water is obtained from the Mississippi River. There are no wells on the ASL site. The future use of the groundwater as a drinking water supply is unlikely because the groundwater is brackish and would require extensive treatment to meet water quality standards. This is considered an eliminated pathway of exposure.

Air: Residents may be exposed to chemicals in the air through breathing. The contaminants in the air maybe found indoors and outdoors. These pathways are considered completed pathways of exposure.

Produce: Residents grow gardens in their backyards. Residents may ingest contaminants when they eat the garden produce. This is considered a completed pathway of exposure.

The pathways of exposure are summarized for each area where residents may come in contact with site contaminants in Tables 1, 2, 3, and 4.

Table 1. Residential Area: Exposure Pathways

Exposure Pathway Media Exposed Population Time
ingestion surface & subsurface soil


produce
residents
workers

residents

past
present
future
past
present
future

skin contact surface & subsurface soil residents
workers
past
present
future
inhalation outdoor & indoor air residents
workers
past
present
future


Table 2. Undeveloped Area: Exposure Pathways

Exposure Pathway Media Exposed Population Time
ingestion surface & subsurface soil trespassers past
present
future
skin contact surface & subsurface soil trespassers past
present
future
inhalation outdoor air trespassers past
present
future


Table 3. Moton School: Exposure Pathways

Exposure Pathway Media Exposed Population Time
ingestion surface & subsurface soil children
teachers
past
present
future
skin contact surface & subsurface soil children
teachers
past
present
future
inhalation outdoor air children
teachers
past
present
future


Table 4. Press Park Community Center: Exposure Pathways

Exposure Pathway Media Exposed Population Time
ingestion surface & subsurface soil children
residents
past
present
future
skin contact surface & subsurface soil children
residents
past
present
future
inhalation outdoor & indoor air children
residents
past
present
future



EXTENT OF CONTAMINATION AND TOXICOLOGICAL IMPLICATIONS OF EXPOSURE

In this section, we will describe the types and amounts of contaminants found in the soil, air, water, produce, and indoor sources. Based on the levels of contaminants reported, we will further explain if health effects are expected to occur from exposures to the contaminants in the soil, air, water, produce or indoor sources.

Soil

Most of the contamination at the ASL site is found in soil. The contamination in soil has been measured at several depths and at 4 locations across the site: residential area, Moton School, Press Park Community Center, and the undeveloped area. This discussion will focus on the levels detected in the 0-3 inch soil samples, since residents will have the most frequent contact with the contaminants in the surface soil. Data collected from the Expanded Site Investigation (ESI) [1], the Remedial Removal Integrated Investigation (RRII) [2], and the RRII Supplemental Sampling Event Report [3] were reviewed for this public health assessment.

The following summary statements describe the extent of contamination and the possible health effects that might occur from exposure to the soil contaminants at the ASL site.

  1. The amount of contamination in the soil varied by location on the site. In general, the highest levels of soil contamination were found in the undeveloped area and the lowest amount of soil contamination was found at Moton School.

  2. Metals and polycyclic aromatic hydrocarbons (PAHs) were the most frequently detected contaminants in surface soil at the ASL site. Pesticides, dioxin, and volatile organic compounds were also found in surface soil, but detected less often than the metals or PAHs.

  3. The levels of metal in the surface soil were highest in the undeveloped area. The lowest levels of metals in surface soil were measured at Moton School.

  4. In most of the developed areas of the site, lead and arsenic levels in the soil are not of concern.

  5. The levels of lead in the surface soil of the undeveloped area are of health concern if the area is developed in the future for residential use without any clean up of the soil.

  6. There are some hot spots of lead contamination in the developed area that, if frequently contacted, could result in increased blood lead levels of young children.

  7. Based on the average arsenic concentrations reported in soil in the developed area, there should be no health effects (noncancer or cancer) expected to occur from contact with the soil.

  8. At the highest arsenic concentrations reported, a young child (1-3 years of age) may experience gastrointestinal irritation from ingestion of the soil located in the undeveloped and developed area of the site.

  9. The highest levels of PAHs were found in very discrete areas of the ASL site: on the undeveloped area, around Gordon Plaza Apartments and Subdivision, at the intersection of Press and Benefit Streets; and east of the recreation center.

  10. Noncancer health effects are not expected to occur from exposure to PAHs in the soil in the undeveloped and developed areas of the site.

  11. There is an unacceptable risk for development of cancer from exposure to the maximum level of PAHs reported in the undeveloped area of the site, if the area is developed for residential use.

  12. Pesticides were generally found in the highest concentrations in the undeveloped area.

  13. The levels of pesticide detected in the undeveloped or developed area do not pose a health threat to current or future residents.

  14. Most of the volatile organic compounds (VOCs) were found either along Almonaster Avenue, on the western side of the undeveloped area or along Benefit street in the northern section of the developed area. The levels of VOCs detected in the soil do not pose a health threat.

  15. The levels of dioxin in all areas of the site were less than the environmental screening value of 1 microgram/kilogram (ug/kg). The highest levels of dioxins were found in the west-southwest section of the undeveloped landfill. The lowest concentrations of dioxins were found in the southern section of the undeveloped landfill and in the Moton School yard. The levels of dioxin reported do not pose a health threat to residents.

  16. Utility workers may have infrequent contact with the contaminants in the subsurface soil. Based on these short-term exposures no health effects are expected to occur in workers from ingestion or skin contact with the soil.

The concentrations reported in the 0-3 inch soil samples were tabulated by area. The minimum to maximum and average values were reported by area (undeveloped area, Moton School, study group homes, and Press Park Community Center). The values reported for the inorganic (metals) are provided in Table 5 and the values reported for the organic compounds (volatile organic compounds, PAHs, and pesticides) are reported in Table 6.

The levels reported were compared to environmental screening values in order that we could determine what chemicals needed to be further reviewed. Screening values used included:

Cancer risk evaluation guideline (CREG): A media specific screening value derived by the Agency for Toxic Substances and Disease Registry (ATSDR) from the Environmental Protection Agency (EPA) cancer slope factor. The CREG represents the estimated contaminant concentration based on one excess cancer in a million persons exposed to a contaminant over a lifetime.

Reference Dose Media Evaluation Guide (RMEG): Media specific comparison values derived from the EPA's reference dose to select contaminants of concern at hazardous waste sites. A reference dose is an estimate of a daily exposure to the general population that is likely to be without appreciable health risk.

Environmental Media Evaluation Guide (EMEG): Media specific comparison values that are used to select contaminants of concern at hazardous waste sites. These values are derived from minimal risk levels which represent contaminant levels below which no adverse health effects are expected to occur.

To determine if exposure to contaminants in the soil posed a threat to residents, workers, or trespassers, the amount of contaminant that a person might incidentally ingest from the soil during work or play was estimated. We assumed that a child (over 5 years of age) or adult might come in contact with the soil in the undeveloped area while trespassing or during work. A child over 5 years of age may consume approximately 200 mg/day of soil from contact with the soil and an adult could consume 100 mg of soil.

In the developed area, we assumed that the most sensitive individual that might come in contact with the soil was a child (1-3 years of age). A child, ages 1-3, may ingest up 5000 mg/day of soil from their hand-to-mouth activities. We estimated what health effects might occur from exposure to the average and the maximum concentration of contaminants in the soil.

Surface Soil - Inorganics

The highest levels of metal contamination were found in the undeveloped area. The lowest levels of metal contamination were reported at Moton School. In general, lead was detected in surface soil in concentrations above 400 mg/kg over much of the ASL site. In the developed area of the site, the majority of the soil samples contained between 100-1000 mg/kg of lead. Pockets of elevated lead were found at the Press Park Community Center and the Gordon Plaza Apartments (greater than 1000 mg/kg). In the undeveloped area of the landfill, lead concentrations were generally above 1000 mg/kg. The maximum lead concentration reported in the undeveloped area of the landfill was 28,300 mg/kg. At Moton School, lead concentrations in the surface soil were below 100 mg/kg, which is consistent with clean fill being added around the school. (See table 5.)

Table 5. Inorganic contaminants in 0-3 inch soil detected in 25% or greater of the samples collected (mg/kg)

Contaminant Undeveloped Area
(min.-max.)
(avg.)
Developed Area & Study Group
(min.-max.)
(avg.)
Press Park
(min.-max.)
(avg.)
Moton School
(min.-max.)
(avg.)
Comparison Value
Aluminum 1690-18,900
(8500)
1680-13,500
(5480)
2470-5900
(4470)
1960-8630
(4510)
none
Antimony 5.2-87.5
(22.9)
5.5-23.8
(12.8)
nd
(nd)
5.9-5.9
(5.9)
0.8
RMEG
Arsenic 1.7-70.7
(25.3)
2.38-62.3
(11.7)
5.95-37.1
(19.7)
1.6-7.7
(3.64)
0.5
CREG
Barium 71.1-1520
(685)
47.6-780
(273)
96.7-812
(502)
49.9-126
(75.8)
100
RMEG
Cadmium 0.67-23.9
(8.15)
0.068-11.7
(3.21)
1.53-3.26
(2.33)
nd
(nd)
1
EMEG
Chromium 6.08-213
(54.3)
5.93-75.4
(26.2)
7.74-75.5
(40.5)
4.4-12.6
(8.5)
10
RMEG
Cobalt 2.7-38.5
(13.1)
1.65-23.2
(8.85)
5.84-14.5
(9.65)
2.7-8.2
(5.2)
None
Lead 37.2-28,300
(1900)
12-2860
(515)
92.7-3090
(1170)
7.3-21
(11.2)
400
EPA SSL
Nickel 7-191
(59)
7.7-85.1
(28.3)
15.1-77
(44)
6.1-18.2
(12.2)
40
RMEG
Vanadium 2.23-46.1
(22.3)
6.7-32.2
(16.4)
12.1-31.3
(22.3)
3.4-21.2
(11.9)
20
RMEG

Exposure to lead is a major health concern especially for young children, since it is particularly harmful to the developing brain and nervous system of the young child. Some investigators have reported decreases in the intelligence quotient (IQ) in children who have been exposed to lead [4].

There are two reasons why children are at greater risk for lead poisoning than adults. First of all, young children tend to exhibit hand-to-mouth behaviors that increase their exposure to lead from their environment. Second, if children consume lead contaminated materials such as soil, house dust, or paint chips, they will absorb more of the lead from their stomachs and intestines than adults will. Children absorb about 50% of the lead they ingest as compared to approximately 10% in adults [4].

Lead was detected in surface soils on most of the ASL site. The levels detected in the residential area were primarily detected in a range of 100-1000 mg/kg. These levels are not unusual for urban areas. The best indicator that lead exposure is occurring is to measure the blood lead level. In the United States, blood lead concentrations are on the average of 3-5 ug/dL. A strong correlation exists between the exposure to lead in the soil and blood lead levels. In general, blood lead levels rise 3-7 ug/dL for every 1000 ppm increase of lead in soil.

Blood lead levels in children that reside over the ASL site have been monitored in the past. According to the Centers for Disease Control and Prevention, a blood lead measure of less than 10 ug/dL indicates that lead poisoning has not occurred. Eighty-two percent of the children tested on the ASL site had blood levels that indicate they have not been lead poisoned. In general, the soil lead levels in the residential area (study group homes, Moton School, and Press Park Community Center) are not elevated. There are however, pockets of contamination in these areas greater than 1000 mg/kg that are of concern, especially if young children routinely play in these areas. The levels of lead reported at Moton School were extremely low and pose no threat to young children.

The levels of lead in the soil in the undeveloped area could pose a health threat if the area is developed for residential use in the future. Currently, there is evidence that individuals are trespassing on the undeveloped area of the site through holes in the fence. It is not known if small children are entering the area and if so, how frequently this occurring. If they are routinely entering the area and playing in the soil, this could increase their lead exposure.

Maintaining the thick grass cover over most of the residential area can act as a barrier in limiting residents' exposure to lead in the surface soil. The grass cover limits the amount of physical contact that an individual may have with the soil.

Arsenic was detected in the surface soil at concentrations between 10-50 mg/kg over most of the developed area. The highest concentrations of arsenic (greater than 50 mg/kg) were detected on the undeveloped area of the site and the study group residences. The lowest arsenic concentrations were reported at the Moton School (less than 7.7 mg/kg). At the average concentrations reported in surface soil, noncancer health effects are not expected to occur from ingestion of the soil at any area of the site. A young child (1-3 years) might experience gastrointestinal irritation, if the soil was ingested every day at the rate of 5000 mg per day from the areas of highest contamination in the undeveloped and developed areas of the site.

Arsenic is a known human carcinogen [5]. Based on the reported soil arsenic concentrations, there is no increased risk for development of cancer in lifetime residents of the developed area of the site. There would also be no increased risk of development of cancer for future residents of the undeveloped area assuming that the property was developed for residential use.

No health effects are expected to occur in residents (adults or children) from exposure to the levels of antimony [6], aluminum [7], barium [8], cadmium [9], chromium [10], nickel [11], or vanadium [12] measured in the soil at any area of the site. It is not expected that dermal contact with the metal contaminants in the soil will produce health effects in residents, since the amount of the metal absorbed from the soil would be very small.

Surface Soil - Organics

PAHs were detected in the surface soil over the entire site (Table 6). Benzo(a)pyrene was detected at concentrations less than or equal to 0.09 mg/kg over most of the site. The highest concentrations were found in the undeveloped area (greater than 10 mg/kg). Two "hot spots" were identified in the undeveloped area at the intersection of Benefit and Press Streets and an area located north of Industry Street and east of Feliciana Streets. The lowest levels of benzo(a)pyrene (less than 0.03 mg/kg) were detected near the Magruder Playground on the Moton School property.

Benzo(a)anthracene, commonly detected in surface soil, was found in concentrations greater than or equal to 0.03 mg/kg over most of the site. The highest concentrations were detected on the undeveloped area of the site greater than 5 mg/kg. Benzo(a) anthracene levels were much lower in the undeveloped area of the site.

Other PAHs including benzo(g,h,i)perylene, chyrsene, indeno(1,2,3-cd)pyrene, naphthalene, and phenthrene were also detected in the surface soil. In general, the levels reported in the undeveloped areas were greater than the developed area of the site.

At the maximum PAH soil concentrations detected in the developed and undeveloped area, there are no expected noncancer health effects from ingestion of the soil by children or adults.

Some of the PAHs have been reported to cause tumors in animals that have ingested or inhaled them [13]. Reports in humans indicate that individuals exposed to mixtures of PAHs for long periods of time can also develop cancer. The most potent PAH is benzo(a)pyrene. In order to determine if exposure to the mixture of PAHs at the site would pose an increased risk for cancer for residents, the total contribution from all the PAHs found in the soil was summed and the cancer risk was calculated for the undeveloped and developed areas of the site. Based on the maximum levels reported in the developed area, there is no increased risk of development of cancer from exposure to the PAHs in the soil. However, based on the maximum concentrations reported in the undeveloped area, there is an unacceptable cancer risk if the area is developed for residential use.

The quantity of PAHs that could be absorbed through the skin during work or play is very small. No health effects are expected to occur from skin contact with the PAHs in the soil.

Table 6. Organic contaminants in 0-3 inch soil detected in 25% or greater of the samples collected in the developed area versus the undeveloped area of the site.

Organic Contaminants Undeveloped Area
Min. - Max.
(Ave. Conc)
in mg/kg
Developed Area
Min. - Max.
(Ave. Conc)
in mg/kg
Comparison Value
Benzo(a)anthracene 0.033-21
(0.00003)
0.041-4.6
(0.311)
none
Benzo(a)pyrene 0.03-20
(1.79)
0.023-5.2
(0.336)
0.1
CREG
Benzo(g,h,i)perylene 0.024-13
(0.999)
0.036-3.1
(0.274)
none
chyrsene 0.035-21
(1.53)
0.023-5.7
(0.358)
none
indeno(1,2,3-cd)pyrene 0.029-14
(0.997)
0.031-2.9
(0.241)
none
napthalene 0.021-0.39
(0.0949)
0.022-0.2
(0.0624)
none
phenanthrene 0.033-6.9
(0.97)
0.025-5.4
(0.294)
none
alpha-chlordane 0.00219-1.3
(0.0474)
0.00193-1.7
(0.123)
0.5
CREG
gamma-chlordane 0.00249-0.11
(0.0177)
0.002-1.8
(0.124)
0.5
CREG
heptachlor epoxide 0.0024-0.0098
(0.00833)
0.0099-0.36
(0.0381)
0.08
CREG

The concentrations of the most frequently detected pesticides (alpha-chlordane, gamma-chlordane, and heptachlor epoxide) in the developed and undeveloped areas of the site were below 1 mg/kg (Table 6). The concentrations of these pesticides in soil of the undeveloped or developed area do not pose a health threat to residents (children or adults) from ingestion or skin contact.

Most of the volatile organic compounds (VOCs) were found either along Almonaster Avenue, on the western side of the undeveloped area or along Benefit street in the northern section of the developed area. The levels of VOCs in the soil do not exceed environmental screening values and do not pose a health threat.

Dioxins were detected in very low concentrations in the residential area, undeveloped area, Press Park Community Center, and Moton School (Table 7). The levels detected were below levels of health concern.

Table 7. Dioxin Concentration in 0-3 inch soil.

Location Minimum to Maximum Concentration
(ug/kg)
Comparison Value
(ug/kg)
Moton School 0-0.0003 1
Open Land 0-0.0071 1
Press Park Community Center 0.0058-0.0866 1
Undeveloped area 0.0007-0.309 1

Subsurface Soil

The concentrations of metals, PAHs, pesticides, and dioxins in the 18-24 inch subsurface soil samples were tabulated (Table 8). Because the contact time a utility worker would have with the subsurface soil is of very short duration, no adverse health effects are expected to occur from dermal contact or incidental ingestion of the soil containing metals, PAHs, pesticides, or dioxins at the reported concentrations.

Table 8. Contaminants Detected in Subsurface Soil On-site (18-24 inches)

Contaminants Average concentration of contaminant detected in subsurface soil
(18-24 inches)
(mg/kg)
Metals

 

Arsenic

32.0

Chromium

67.0

Lead

1620.0

Cobalt

13.81

VOCs

 

tetrachloroethene

0.0385

PAHs

 

benzo(a) anthracene

1.13

benzo(a) pyrene

1.26

benzo(b)fluoranthene

1.81

fluoranthene

1.41

Pesticides

 

alpha-chlordane

0.019

gamma-chlordane

0.02237

4,4'-DDT

0.0217

endrin

0.0139

Air

Outdoor and indoor air samples were collected from off-site areas (background) and areas on the ASL site. The outdoor air samples were collected from the back yards or side yards of the ranch homes and town houses and from the common areas of the apartment complexes. Outdoor air samples were also collected from Moton School and the undeveloped area. Indoor air samples were collected from the study group residences, background residences, and Moton School. One indoor air sample was collected from the main bedroom of each home.

Additional indoor and outdoor air samples were collected on-site during the 1995 Supplemental Sampling Event Report in order to verify the level of contaminants and their sources. The sampling locations chosen for indoor air had the highest ambient air chloroform concentrations as measured in the 1994 investigation.

Outdoor Air

The levels of volatile organics reported in outdoor air do not pose a health threat from short-term exposures. It is not known if the levels measured are representative of long -term exposures. Volatile organic compounds (VOCs) were detected in off-site (background) and on-site air samples in the RRII (Table 9). Similar levels of VOCs were found in on-site air samples in the supplemental RRII. The levels detected for all on-site locations were comparable to levels usually found in urban air (Table 10). There were no significant differences in the concentrations detected in the developed area versus the undeveloped areas of the site. The VOCs found in surface soil did not correspond with the compounds found in the outdoor air samples. It is most likely that the contaminants in the outdoor air samples were from sources other than the site. These sources could include motor fuels, household products, and refrigerants.

Methane is produced naturally when materials degrade and is commonly found at landfills. At ASL, methane was not detected in the outdoor air samples during the 1994 RRII. It was detected at low concentrations in two out of three outdoor samples in the 1995 supplemental sampling (maximum detected, 22 ppm). The former landfill site is believed to be the source of this methane [3].

Table 9. Average Concentrations of Contaminants Detected in Outdoor Ambient Air Samples1

Contaminant Background Residences
(avg.conc.)
ppb2
Study Residences
(avg. conc.)
ppb
ASL Developed
(avg. conc.)
ppb
ASL Moton School
(avg. conc.)
ppb
1,1,1-trichloroethane 0.22 0.659 nd nd
1,2,4-trimethylbenzene 0.32 0.374 0.28 0.29
1,3,5-trimethylbenzene nd3 0.37 nd nd
1,3-dichlorobenzene nd 0.51 nd nd
1,4-dichlorobenzene 0.24 1.77 nd nd
benzene 0.856 3.23 1.3 0.81
chloroform nd 17.1 nd nd
chloromethane 0.336 0.333 nd nd
ethylbenzene 0.247 0.367 0.225 nd
Freon 11 0.374 0.804 0.37 0.3
Freon 12 0.582 0.671 0.565 0.46
methylene chloride nd 0.3 nd nd
m,p-xylene 0.774 0.995 0.695 0.46
o-xylene 0.286 0.39 0.25 0.2
toluene 1.48 1.84 1.3 0.85
Freon 113 nd 0.26 nd nd
tetrachloroethene nd 0.205 nd nd
trichloroethene nd 0.485 nd nd
1 From the 1994 RRII
2 ppb - parts per billion
3 nd = not detected


Table 10. Comparison of Outdoor Air Samples on ASL Site versus National Toxics Data Base Air Levels1

Contaminant National Toxics Data Base
(median)
ppb2
Background Residences
(max.)3
ppb
Study Residences
(median)
ppb
ASL Moton School
(max.)3
ppb
ASL undeveloped area
(median)
ppb
1,1,1-trichloroethane 0.40 0.22 0.26 nd nd
1,2,4-trimethylbenzene 1.00 0.51 0.34 0.28 0.28
1,3,5-trimethylbenzene 0.20 nd4 0.37 nd nd
1,3-dichlorobenzene 0.01 nd 0.51 nd nd
1,4-dichlorobenzene 0.05 0.24 0.40 nd nd
benzene 1.81 1.1 0.94 0.81 1.6
chloroform 0.06 nd 0.41 nd nd
chloromethane 0.81 0.46 0.31 nd 0.53
ethylbenzene 0.62 0.27 0.30 nd 0.24
Freon 11 0.36 0.44 0.35 0.37 0.39
Freon 12 0.73 0.67 0.58 0.565 0.60
methylene chloride 0.84 nd 0.3 nd nd
m,p-xylene cnr5 0.89 0.93 0.46 0.74
0-xylene cnr 0.33 0.35 0.20 0.25
toluene cnr 2.0 1.30 0.85 1.4
Freon 113 cnr nd 0.26 nd nd
tetrachloroethene 0.37 nd 0.21 nd nd
trichloroethene 0.21 0.5 0.46 nd nd
1 From the 1994 RRII
2 ppb - parts per billion
3 Maximum was reported when there were insufficient readings to calculate a median.
4 nd = not detected
5 cnr = compound not reported

Indoor Air

Based on the short duration indoor air samples, the indoor air contamination does not pose a health threat for residents. It is not known if the levels measured in indoor air are representative of long-term exposure. The primary contaminants measured in indoor air during the RRII are listed in Table 11. Methane was most frequently detected in residences that used natural gas. Chloroform, Freon 11, or Freon 12 were found in 96% of the indoor samples.

The levels reported do not exceed levels that would produce health effects from short-term exposures. Because samples were obtained for only a one hour period, it is not known if the levels reported are representative of the long-term levels in indoor air.

The 1995 supplemental investigation provided a longer sampling period of indoor air (8 hours) during low activity times in order to reduce the man-made sources of chloroform and other VOCs. Only the three homes which previously had the highest chloroform concentrations were resampled. No chloroform was detected in these residences during the 1995 investigation. Other VOCs levels were similar to the earlier investigation, except for 1,4-dichlorobenzene, which was estimated at 500 ppb in one home.

Although 1,4-dichlorobenzene is above Cancer Risk Evaluation Guideline levels, it is less than acute comparison values. This chemical is a commonly used in the manufacture of mothballs and deodorant blocks used for garbage cans and toilets. The presence of this chemical is probably not site-related. Therefore, we cannot determine if health effects would result from long-term exposure to indoor contaminants.

Table 11. Average Concentration of Compounds Detected in Indoor Ambient Air Samples1

Contaminant Background Residences
(ppb)2
ASL Study Group
(ppb)
ASL Moton School
(ppb)
1,1,1-trichloroethane 0.992 1.21 4.4
1,2,4-trichlorobenzene 0.21 0.57 nd
1,2,4-trimethylbenzene 0.868 2.12 1.2
1,3,5-trimethylbenzene 0.3 0.976 0.445
1,4-dichlorobenzene 5.67 31.5 0.26
1,1-dichloroethene nd3 0.36 nd
1,2-dichlorobenzene nd 0.26 nd
1,3-dichlorobenzene nd 980 nd
chlorobenzene nd 0.9 nd
chloroethane nd 0.33 nd
benzene 3.11 2.54 1.5
chloroform 0.475 12.6 0.32
chloromethane 0.408 0.56 0.42
ethylbenzene 0.712 1.35 0.56
Freon 11 1.76 1.2 54.5
Freon 12 0.9 0.93 7.7
m,p-xylene 2.54 4.25 nd
o-xylene 0.874 1.63 0.77
methylene chloride 0.26 1.15 nd
methane 25.1 16.4 nd
toluene 7.52 8.18 0.39
Freon 113 nd nd 31
styrene 0.625 0.674 0.315
tetrachloroethene 1.38 1.8 nd
trichloroethene nd 0.765 nd
1 From the 1994 RRII
2 ppb - part per billion
3 nd = not detected

Air Intrusion Studies

Methane has not been detected at levels that would pose an explosive hazard in housing or sewers on the ASL site. Volatile organic compounds (VOCs) were not migrating from the surface soil.

The air intrusion study was conducted to determine if methane and/or other VOCs had build up in and around residences, Moton School, or within drainage systems (storm, sewers, and catch basins). Methane was detected outside of 3 study homes at low levels. Methane may build up to levels that may produce an explosion. The levels detected were well below explosive levels and pose no hazard. No VOCs were positively detected on any outdoor surveys of the homes.

Methane was detected in one indoor air sample from ten residences (maximum value up 50 ppm). This level is well below the explosive limit for methane. The source of the methane may be from use of natural gas. Five of these 10 residences used natural gas. VOCs other than methane were detected at 2 of the 10 study residences (10 ppm and 20 ppm).

Storm drain and catch basin results did not show any VOC or methane patterns that indicate that the landfill is off gassing. Methane was detected in storm drains (3-45 ppm) and sewer manholes (maximum reported 1000 ppm). These values are not considered to be elevated and do not pose an explosive hazard.

Soil Gas Sampling

Methane was detected at elevated levels in soil gas measurements. However, the indoor air and air intrusion studies did not show a migration of methane that would pose an explosive hazard. Further investigations are needed to confirm that methane is not significantly migrating into buildings from the landfill [14].

The soil gas sampling that was done during the 1994 RRII was determined to be unusable and had to be repeated during the 1995 supplemental investigation. Soil gas measurements in 1995 did confirm high levels of methane exist below ground surface on-site. During this investigation, 16 on-site geoprobe measurements were made at 13 locations. Five of the 13 locations sampled did not measure methane above the detection limit of 5 parts per billion (ppb). Five measurements exceeded 25% of lower explosive limit. Only three of the 13 locations sampled exceeded the lower explosive limit (LEL, approximately 50,000 parts per million). Two of the highest measurements of methane were in the undeveloped portion of the landfill, a third exceedance of the LEL was near the Moton School.

The soil gas investigation also confirmed the lack of any significant quantity of non-methane volatile organic chemicals often found in hazardous waste sites. The lack of these volatile compounds indicates methane is being produced from bacteria decomposing vegetation and "old fashion" domestic waste generated prior to the mid-1960s. Methane gas is a safety hazard because of possible fire and explosion problems. Landfill gas generated at ASL is very similar to the natural gas used by many of the households located on the landfill and does not pose a health risk from daily inhalation exposure.

The presence of natural gas appliances in household and natural gas pipelines on site complicates determination of the source of high methane concentrations reported at the 3 soil gas sample locations. Also complicating the determination of the source is the lack of periodic and extensive soil gas monitoring. As revealed by multiple years of monthly soil gas monitoring at other NPL sites, methane concentrations are not uniform but change often from below detection limit to above the LEL from one sampling period to the next. Landfill gas may not be uniformly distributed across a landfill. Landfills often produce very localized, "hot spots" of methane above the LEL while other areas are well below LEL.

Despite the presence of high concentrations of landfill gas in the subsurface outside a building, landfill gas may not be entering the building. All soil gases tend to move from areas of high pressure to areas of low pressure. If subsurface pressure of the landfill gas is consistently lower than indoor air pressure, significant concentrations of landfill gas will not enter the building. Where pressure differences are sufficient for movement of landfill gases into buildings, landfill gas tends to enter via the most permeable areas in the building such as via utility lines (water, sewer, electric and natural gas) and cracks in foundations, as caused by subsidence.

The 1994 remediation investigation did include methane as one of the gas analytes in indoor air, outdoor air, and air intrusion studies. Only 7 residences out of the 33 checked had any methane detected and that was at very low concentrations. Five of these homes used natural gas appliances. None of the indoor air samples contained significant concentrations of methane.

Indoor Dust Samples

The dust samples obtained from the ASL study group homes do not indicate that excessive exposure to lead is occurring from contact with indoor dust. Three dust samples were collected from the inside of each study group residence and analyzed for lead. Lead was detected in all indoor dust samples in the 33 on-site residences. The maximum concentration reported was 939 mg/kg, the second highest concentration was 375 mg/kg. The average indoor lead dust concentration was 126 mg/kg.

Small children may ingest dust from mouthing their hands, toys, or food that may have come in contact with dust in the home. A review of the studies that compared the increase in blood lead in children with the increase reported in soil lead indicated that there should be an increase of 3-7 ug/dL in blood lead for every increase of a 1000 mg/kg of lead in soil [15]. All but one of the homes on the ASL site were below 380 mg/kg, indicating that the indoor dust was not significantly increasing the blood leads of children residing in these homes.

Indoor and Outdoor Paint Samples

Based on the measurements taken from painted surfaces in the study group homes, ingestion of leaded paint does not appear to contributing to increased lead exposure of the children that reside in these homes. A potential source of lead exposure for a small child is the ingestion of flaking or chipping paint from window sills and baseboards in the home. Paint chips were collected from flaking or peeling paint in the study group homes and analyzed for lead. Lead was not detected in the indoor paint chips of the ASL homes.

Seven samples of paint chips from exterior doors of the ASL homes did contain lead. The paint chips were found on the front or back doors of town houses and apartments located on Press, Treasure, and Benefit Streets. It is not known how much contact that a young child would have with this source of lead, therefore we cannot determine if it is contributing to increases in lead exposure.

Tap Water Samples

The tap water in the study group residences and Moton School does not contain contamination at levels that would pose health effects. Tap water samples were taken from the study group residences and Moton School. One sample was taken from the first draw from the tap and the second sample was taken after the water was allowed to run for 3 minutes. There was a slightly lower concentration of metal in the samples after the water was allowed to run for three minutes indicating that there may be some contamination from the plumbing.

Arsenic was detected in one water sample out of the 33 homes tested. The arsenic value exceeded the environmental comparison value, however exceedance of this value does not indicate that a health effect will be produced. The value which the sample exceeded was a cancer risk evaluation guide. Arsenic has been shown to produce cancer (skin cancer) when it is ingested from food or water on a long-term basis at much greater than the level reported in the study group home. Therefore, residents are at no increased risk for cancer from drinking the tap water at the reported arsenic concentration.

All but one of the tap water samples tested for lead were below the maximum contaminant level (MCL). The MCL is a drinking water standard which is the maximal allowable level of a contaminant in the water, that an individual consuming 2 liters of water a day over a lifetime can be exposed to. There was a slight exceedance of the MCL in a first draw sample (value of 17 ug/L versus MCL value of 15 ug/L). The three minute purge sample values were well below the MCL. The first draw sample was collected after the water had been retained in the plumbing for a period of time. This indicates that there may be some source of lead from the plumbing that increases the lead content of the water. Once the plumbing is flushed, the lead concentration in the water is at a level that is considered as a safe water supply.

Table 12. First Draw and Purge Tap Water Samples: Study Group Residences and Moton School.

Contaminant Study Group Residences
1 min1
(ug/L)
Study Group Residences
purge2
(ug/L)
Moton School
1 min
(ug/L)
Moton School
purge
(ug/L)
Comparison Value
Exceeded?
Yes/No
Arsenic nd4 3.2-3.2 nd nd 0.02 CREG
yes
Aluminum 115-115 nd nd nd none
Barium 21-31 21-31 26-28 27-29 700 RMEG
no
Lead 3.1-17 3-7.6 3.1-6.2 3.7-3.7 15 MCL
yes
Selenium 3.8-3.8 3.2-3.2 nd 3.3-3.3 20 EMEG
no
Zinc 21-89 28-28 27-27 nd 3000 RMEG
no
1 - 1 minute samples are water samples collected from the tap for 1 minute without flushing the plumbing.
2 - purge samples are water samples collected after the water has run from the tap for 3 minutes.
nd = not detected; ug/L = micrograms per liter.

Garden Produce

Based on the levels of metals and pesticides measured in the garden produce, the vegetables grown on Agriculture Street Landfill should be safe to eat. The vegetable crops have been sampled two times. In 1984, seven garden soil samples were collected from Agriculture Street Landfill. The garden soil samples were analyzed for mercury and lead. It was found that mercury levels in the garden soil samples ranged from 0.1-1.7 mg/kg. Lead levels in the garden soil ranged from 52-3002 mg/kg. Vegetables were collected from the residence with the highest soil lead level (3002 mg/kg). Lead was detected in squash, cucumbers, and tomatoes at the levels reported in Table 13. Mercury levels were not measured in the vegetables.

Table 13. Lead Content: Vegetable Samples 1984.

Lead in Soil
(mg/kg)
Vegetable Crop Lead Content in Vegetables Collected on Ag. St. Landfill
(mg/kg)
Lead Content Normally Found in Vegetables
(mg/kg) [2]
3200 squash 0.23 0.005- 0.649
3200 cucumber 0.40 0.005- 0.649
3200 tomatoes 0.72 0.005- 0.649

The amount of lead a person would ingest from the vegetables is below levels that would produce harmful health effects. Furthermore, the lead levels detected in the squash and cucumber are in the range of lead levels found routinely in vegetables. The levels reported in tomatoes were slightly above the upper range routinely found in vegetables. The reason that the lead levels are not elevated in the vegetables is because plants do not tend to take up much lead from the soil. Lead tends to bind to the organic matter in the soil.

In 1994, carrots, garlic, squash, parsley, and cabbage were collected from gardens in the Agriculture Street Community. The vegetables were analyzed for metals (arsenic, lead, cadmium, and mercury) and pesticides. Arsenic, lead, and mercury were not detected in the vegetables. Cadmium was detected in four vegetable samples at the levels reported in Table 14.

Table 14. Cadmium content of Vegetables

Cadmium in Soil
(mg/kg)
Vegetable Crop Cadmium Content of Vegetable
(mg/kg)
Cadmium Content Routinely Found in Vegetables
(mg/kg) [2]
2.0 carrot 0.6 trace-0.0159
2.0 parsley 0.0328 0.016-0.061
8.0 garlic 0.35 trace-0.0159
8.0 cabbage 0.25 0.016-0.061

The levels of cadmium in carrots, garlic, and cabbage were greater than levels routinely found in vegetables. Even though the cadmium levels exceed those routinely found in vegetables, the amount of cadmium a person would ingest from these vegetables would not produce health effects.

Diazinon, trifluralin, and malathion were found in vegetables sampled from Agriculture Street Landfill residences. The levels found are reported in Table 15.

Table 15. Pesticide Concentration in Vegetables---Agricultural Street Landfill

Vegetable Diazinon
(mg/kg)
Diazinon Regulatory Value
(mg/kg)
Trifluralin
(mg/kg)
Malathion
(mg/kg)
carrots 0.029 0.1-60 n.d. 0.006
parsley 2.1 0.1-60 n.d. n.d.
cabbage 0.002 0.1-60 0.014 0.002
garlic 0.002 0.1-60 0.004 n.d.

The levels of diazinon, malathion, and trifluralin that a person would ingest from the vegetables are below levels that would cause health effects. Diazinon, malathion, and trifluralin are products that can be purchased by gardeners for control of insects and weeds. These compounds remain in the soil for a period of a few days to a few weeks. There were no Food and Drug Administration standards for the amount of malathion, diazinon, or trifluralin that can be found in food. The diazinon levels reported are in the range considered safe for agricultural products by the EPA. Malathion is an insecticide that does not produce significant toxicity in humans. A regulatory standard for the amount of malathion that can be found in raisins was found under 40 CFR 1995 for raisins (12 mg/kg). The levels in the carrot and parsley samples are well below this limit. Trifluralin has a low degree of toxicity to mammals. Under 40 CFR 1995, a limit of 2 mg/kg of trifluralin was established for peppermint and spearmint oil. The levels found in the cabbage are well below this value.

Eggs

There was no contamination found in chicken eggs that ranged on the site. Eggs from hens that free ranged yards on the ASL site were analyzed for lead by the Louisiana State University in 1994. Lead contamination was not detected in the shells or contents of the eggs [16].


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