Urban soil-lead (Pb) footprint: retrospective comparison of public and private properties in New Orleans
←
→
Page content transcription
If your browser does not render page correctly, please read the page content below
Environ Geochem Health
DOI 10.1007/s10653-007-9111-3
ORIGINAL PAPER
Urban soil-lead (Pb) footprint: retrospective comparison
of public and private properties in New Orleans
Howard W. Mielke Æ Christopher Gonzales Æ
Eric Powell Æ Paul W. Mielke Jr.
Received: 18 April 2006 / Accepted: 4 July 2007
Springer Science+Business Media B.V. 2007
Abstract Lead (Pb) is a toxin that after childhood communities. The data were analyzed using multi-
exposure poses a lifetime of health risks. One route of response permutation procedures (MRPP). The soil-
exposure is soil-Pb as a result of *12 million metric Pb results differ significantly (P-value < 0.001) on
tons of Pb residue in paint and gasoline sold in the US same-aged HANO properties at different locations;
during the 20th Century. Pb accumulated in soil of thus, year of construction does not give adequate
the community is a good predictor for blood Pb of explanation for the soil-Pb differences. HANO and
children living there. This retrospective study com- RES soils are significantly more Pb contaminated in
pares the soil-Pb on Housing Authority of New the CORE than in OUTER communities (P-value <
Orleans (HANO) properties with adjacent private 0.001). The CORE has many more years of traffic
residential (RES) properties within a 0.8 km congestion than OUTER communities; therefore, the
(0.5 mile) radius. The sample subset (n = 951) is lead additives to gasoline, and not lead-based paint,
from two soil-Pb surveys (total n = 9,493) conducted best elucidate the differences of the soil-Pb footprint
between 1989 and 2000. The properties were in both at HANO and RES properties in the CORE and
the inner city (CORE) and outlying (OUTER) OUTER communites. Currently HANO properties
are being redeveloped with cleaner soil, but soil on
RES properties in the CORE of New Orleans remains
H. W. Mielke
a large source of Pb (median = 707 mg/kg in this
Department of Chemistry, Tulane University,
New Orleans, LA 70118, USA study) for human exposure, especially children.
H. W. Mielke (&) Keywords Urban geochemistry
Center for Bioenvironmental Research, Tulane
Built environment MRPP statistics
University, 1430 Tulane Avenue SL-3, New Orleans,
LA 70112, USA Environmental health disparities
e-mail: howard.mielke@gmail.com
C. Gonzales
Introduction
College of Pharmacy, Xavier University of Louisiana,
New Orleans, LA 70125, USA
Lead (Pb) is a neurotoxic element at blood Pb
E. Powell measurements less than 10 lg/dl (Canfield et al.
Lead Lab, Inc., New Orleans, LA 70179-1125, USA
2003). In pre-Katrina New Orleans, childhood ele-
P. W. Mielke Jr. vated blood Pb (i.e., 10 lg/dl) was epidemic and
Colorado State University, Fort Collins, CO 80523, USA affected *25% of the inner city children and *12%
123
Environ Geochem Health of the children of the entire city (Louisiana Office of current (i.e., 2007) techniques to compare retrospec- Public Health). From the perspective of environmen- tive soil-Pb data collected on HANO and neighboring tal health, the cost of lead poisoning in the U.S. is RES properties. This task is undertaken to improve estimated at 2.2% of the total healthcare costs or understanding of the soil-Pb footprint and its impact $43.4 billion (Landrigan et al. 2002). The costs on health in New Orleans. include direct treatment and other costs such as special education and reduced lifetime earning abil- ity. One example of the possible health costs for New Methods Orleans is that children exhibited a pattern of diminished school achievement associated with the A unique feature of this study is that it is based on a amount of Pb and other metals within their school subset of soil samples from two extensive, city-wide district (Mielke et al. 2005a). If the pre-Katrina costs soil metal surveys. Both surveys were conducted for childhood Pb poisoning were proportional to the before the August 29, 2005 catastrophic flood of New national estimates, then in New Orleans costs were Orleans associated with the storm surge of Hurricane *$76 million annually (Mielke et al. 2006a). Other Katrina and prior to the HOPE VI Demolition and societal problems related to elevated Pb exposures Revitalization Grants that began in the late 1990s to include violent crime, diabetes, and unwed preg- the present (HOPE VI). Because these public housing nancy, all of which have implications to an array of grants have funded the demolition and the renewal of social, medical, and psychological outcomes and the public properties with new residential housing, costs (Needleman et al. 2002; Tsaih et al. 2004; many of the former HANO buildings have been or are Nevin 2000). Research has shown that the Pb in the process of being razed. Thus, for the former accumulated in soil is a strong predictor for blood HANO properties in New Orleans the survey data are Pb of children in the community (Sayer et al. 1974; historic and do not necessarily reflect current soil-Pb Mielke et al. 1999; Johnson and Bretsch 2002). In conditions of the redeveloped properties. On the other addition, in urban settings, because soil moisture is hand, the data do provide relatively current informa- directly related to suspension of Pb dust, soil tion about the soil-Pb content on the neighboring moisture is closely associated with seasonal varia- private residential properties where redevelopment tions of blood Pb levels; that is, increasing during and renewal has not occurred. The storm surge periods of low soil moisture and decreasing during flooded 80% of New Orleans and did not appear to periods of high soil moisture (Laidlaw et al. 2005). make a significant change to the Pb content of New Some public health professionals claim that Pb- Orleans soils (Mielke et al. 2006b). based paint alone determines the footprint for Pb and Advances in computer technology and geographic consequently the childhood exposure to Pb (Brown information science (GIS) techniques that evolved and Jacobs 2006; Clark et al. 2004). In contrast, there after completing Survey 1 (1992) were applied to is a body of literature suggesting that Pb accumulates collecting, mapping and analyzing soil metals for in soils from multiple sources, and particularly from Survey 2 (2000). Also, our ability to investigate the two main sources, paint and gasoline, determine the results of Surveys 1 and 2 was profoundly enhanced footprint, and hence childhood Pb exposure (Reagan by advances in computing power, software, and and Silbergeld 1989; Filippelli et al. 2005; Laidlaw statistics. et al. 2005; Mielke and Reagan 1998; Johnson and Bretsch 2002). This divergent opinion is critical because it has implications regarding steps needed to Sample collection for New Orleans soil surveys protect children in urban areas from exposure to Pb. This paper focuses on the soil-Pb footprint at The collections of soil samples were stratified by public housing and neighboring residential properties census tracts of New Orleans. Our purpose was to of New Orleans. The public properties were managed systematically collect as many soil samples as by the Housing Authority of New Orleans (HANO) feasible, within the budget available, to study the and the neighboring residential properties (RES) were distribution of soil metals, including Pb, in the urban managed privately. The purpose of this paper is to use environment. Each collected soil sample represents 123
Environ Geochem Health
one of three types of sites (street side, house side or (N = 286) plus City Park. Sampling was conducted
foundation, and open space) at a single urban location using U.S. Census Bureau Topologically Integrated
and this information is translated into a dot on a map. Geographic Encoding and Referencing (TIGER) 97
The methods of the two soil surveys were essentially maps as a guide. This was a major innovation because
the same. All samples were collected from the top it simplified tracking boundaries of each census tract
2.5 cm (1 inch) surface of the soil and extracted with and the location of each collected soil sample. Also,
similar methods. Survey 1, however, provided infor- another change was to hire an additional project staff
mation that suggested ways for improving Survey 2. member to organize, collect, and process the soil
As a result of the improvements, we have more samples. Wherever possible, 19 samples instead of 15
confidence in the results of Survey 2 than Survey 1. were collected from each census tract as follows: 10
The differences in the surveys are described below: samples were collected within 1 m of a residential
street (ST) at least one block from the busiest street; an
additional category included the busiest street—4
Survey 1 (completed in 1992) samples were collected within 1 m of busy streets
(BS) for the purpose of comparing the quality of
Survey 1 was conducted from 1989 through 1992 residential street (ST) samples to busy street (BS)
(Mielke 1994; Mielke et al. 1997, 1999). The 1980 samples; three samples, each matched with street side
Census Tracts (n = 283) were used to stratify the soil samples, were collected within 1 m of house sides or
samples. The total number of samples collected for foundations (FN); and, two samples were collected
Survey 1 was 4,026. Maps for field work were from open space (OS), i.e., vacant land or parks as far
prepared by marking the boundaries of each census as possible from streets and house sides. Analytical
tract by hand on a New Orleans street map prior to equipment had become several times more sensitive
soil collections. One staff member and several than that available for Survey 1, and thus, in the
student workers were employed to conduct the soil laboratory 0.4 g instead of 4.0 g of soil were used for
collections. In the field, wherever possible, 15 extractions at room temperature with 20 ml trace metal
samples per census tract were collected according grade 1 M HNO3 resulting in a 1:50 dilution. This
to the following scheme: all samples were collected laboratory change was important because it eliminated
at least one block from a busy street and away from concurrent errors connected with sample dilutions and
street corners; 10 samples were collected within 1 m reduced the amount of time required for conducting
of the street (ST); three samples, each matched with repeat analyses. Comparison of the two surveys
street side samples, were collected within 1 m of showed similarities although some differences were
house sides or foundation (FN); and, two samples present (Mielke et al. 2005b). The data obtained from
were collected from open spaces (OS), vacant land or the two surveys are the basis for this study.
parks as far as possible from streets and house sides.
In the laboratory, soil extractions were prepared at
room temperature using 4.0 g of soil with 20 ml trace HANO public housing properties and RES
metal grade 1 M HNO3. The 1: 5 samples were housing
diluted as necessary and analyzed by inductively
coupled plasma atomic emission spectrometry (Mi- The HANO properties in New Orleans and the
elke et al. 1999). corresponding 0.8 km (0.5 mile) radii of surrounding
RES properties are shown in Fig. 1. Note that there
were ten HANO public properties located in New
Survey 2 (completed in 2000) Orleans. While the entire sample base for the two
surveys is 9,493 soil samples, this study is from a
Survey 2 was begun in 1998 and completed in 2000 subset of samples. The Survey 1 samples consisted of
(Mielke et al. 2000; Mielke 2002; Mielke et al. 2002; 133 and 265 for HANO and RES, respectively. The
Mielke et al. 2006a). The total number of samples Survey 2 sample subset consists of 219 and 334 for
collected for Survey 2 was 5,467. The soil samples HANO and RES, respectively, for a total n = 951 for
were stratified according to the 1990 Census Tracts this study.
123Environ Geochem Health
Fig. 1 Map of the HANO
public housing and the
residential RES properties
within a radius of 0.8 km
(0.5 mile). The properties
without star (*) notations
are located in the core areas
of New Orleans. At the time
of construction, the starred
HANO housing (*) were
located in the outer areas of
New Orleans
MRPP statistical tests 2007). In most investigations, the population distri-
bution will never be known. Furthermore, assuming
Multi-response permutation procedures (MRPP) are an inappropriate distributional model will most likely
used to compare g sets of cases where each case occur and leads to invalid statistical inferences. The
involves multivariate responses and are described in normal distribution is an inappropriate model for
detail by Mielke and Berry (2007). A version of many ecological data, which most often are skewed,
MRPP was applied to the first study of urban soil discontinuous, and multi-modal. When sample sizes
metals conducted in Baltimore in the mid-1970s are small, large sample approximate methods often
(Mielke et al. 1983). While MRPP are a family of are questionable. Permutation procedures make effi-
statistical tests based on various distance functions, cient use of small sample sets, because probabilities
the simple Euclidian distance used here is the can be calculated exactly by complete enumeration of
intuitive choice of distance functions for evaluating all possible combinations under the null hypothesis,
the relationships of these data sets. The distance otherwise, resampling or Pearson type III approxi-
function between the r multivariate values of the Ith mations are needed; the latter are used here because
and Jth cases, i.e., (x1, I,…, xr, I) and (x1, J,…, xr, J), is very small probability values (P-values) are encoun-
given by tered. Of greater importance, the permutation testing
" #1=2 framework allows us to use exceedingly robust
X
r 2 statistical tests based on distance functions such as
DI;J = xh;I xh;J . Euclidean distance. Euclidean distances yield the
h¼1
ordinary geometrical interpretation of distance by
For completeness, if mi is the number of cases in investigators in any applied field of science. Most
ith of g data sets (i = 1,…, g), then the efficient conventional parametric and nonparametric methods
MRPP weight function is given by ci = mi/ are based on squared Euclidean distances as a
(m1+ + mg). consequence of statistical analyses based on least
Euclidean distance has the property of being a squares (Mielke and Berry 2007). Statistics based on
metric that yields an analysis space that is congruent squared Euclidean distances are non-metric because
with the data space in question (Mielke and Berry they violate the triangle inequality property of a
123Environ Geochem Health
metric, and consequently they have no simple CORE of New Orleans prior to the expansion of the
geometrical interpretation for the r response variables boundaries of the city into the previous wetlands of
associated with the r-dimensional data space in the Lake View Neighborhoods along Lake Pontchar-
question. The results are given as P-values, i.e., the train and into the low-lying coastal wetlands of East
probability of having a more extreme outcome by New Orleans.
chance alone. Thus a very small P-value (near 0) The six CORE HANO housing [abbreviation]
suggests that the outcome is most likely not attributed (year of construction) and 1990 Census Tracts are
to chance alone. In contrast, a large P-value (say from given below:
0.1 to 1) suggests the outcome is not a questionable
• St. Thomas [STH] (1941) census tracts 81.01 and
outcome, i.e., it could easily be attributed to chance
81.02
alone. More information about MRPP statistics and
• C.J. Peete [CJP] (1941 and 1955), census tract
software can be obtained from the following sources
93.02
(Mielke and Berry 2007; Blossom 2005).
• Iberville [IBE] (1941), census tract 48.00
• Lafitte [LAF] (1941), census tract 44.02
• Guste [GUS] (1964), census tract 68.00
Results and discussion
• B.W. Cooper [BWC] (1941), census tract 69.00
Surveys 1 and 2 follow the same strong trend of soil- At the time of their construction, four HANO
Pb within the metropolitan area of New Orleans housing properties were built at the edge of the city of
(Mielke et al. 2005b). Survey 2, the soil collection New Orleans, and as a result, they are referred to as
effort that benefited most from the improved software OUTER properties. The four OUTER HANO prop-
and computer technology, is used to illustrate the erties [abbreviation] (and their year of completion)
soil-Pb map of New Orleans. Figure 2 shows red dots and 1990 Census Tracts are listed below:
at locations with the highest quartile (75–100
• Desire [DES] (1957) census tract 17.98
percentiles encompassing a range of soil-Pb from
• Florida [FLO] (1946 and 1953), census tract
330 mg/kg to 52,798, respectively,
16.00
(95% = 2,138 mg/kg) and the blue locations of the
• St. Bernard [STB] (1940 and 1960s), census tract
lowest quartile (0–25 percentiles encompassing a
33.06
range of soil-Pb from 3 mg/kg to 37 mg/kg, respec-
• Fischer [FIS] (1965), census tract 6.01
tively); the mid range soil samples (26–74 percentile
of 38 mg/kg to 329 mg/kg, respectively) are shown The neighboring RES properties within 0.8 km
with gray dots. The median soil-Pb of the entire (0.5 mile) radii of each public housing project were
sample set (n = 5,467) is 112 mg/kg. The highest assigned to the same CORE and OUTER grouping as
quartile of soil-Pb samples (red dots) are clustered in their associated HANO properties.
the inner city and the lowest quartile of soil-Pb (blue
dots) are scattered outside of the inner-city. Thus, the
areas of the older inner-city (CORE) of New Orleans Age of construction and Pb based paint
have the highest probability for encountering large
amounts of soil-Pb. There is a decreased probability Age of construction is commonly used as a surro-
of encountering high soil-Pb concentration in samples gate for the risk of Pb exposure. Paint products
with increasing distance away from the CORE containing Pb were first used in the late 19th century
communities of New Orleans. and then increased up to the mid-1920s when Pb-
The focus of this study is on soil-Pb of a subset of based paint production peaked. The Pb content in
samples (n = 951) from the two soil surveys. The ten paint slowly decreased until it was banned for
HANO public properties and their associated RES residential use in 1978. The total tonnage of Pb was
properties were stratified into two groups, CORE and *6 million tons (Mielke and Reagan 1998; Mielke
OUTER because of their locations within the context 1999). The reason that age of construction is
of the historic development of New Orleans (see considered as a factor is because there was a
Figs. 1, 2). Six of the complexes were built in the decrease in the Pb content of Pb-based paints after
123Environ Geochem Health the peak use in the 1920s. Thus, if the idea is Comparison of the Pb accumulated on each correct, age of the HANO properties should be a HANO project and in adjacent private residential defining variable in the quantity of environmental (RES) properties Pb associated with each location. There are two sets of HANO properties that share The soil-Pb results from the two groups, HANO and similar dates of construction but are located in RES, were compared (see Fig. 2). For St. Thomas the different parts of New Orleans. The first case is centroid for the combined census tracts was used as Florida and C.J. Peete that were both constructed in the origin for the radius. Tables 2 and 3 summarize the 1940s and expanded in the 1950s. Florida is the results for Surveys 1 and 2 for HANO and RES located in OUTER and C.J. Peete is located in the properties, respectively. CORE of New Orleans. Table 1 shows the Pb results Table 2 shows Survey 1 results of soil-Pb from of these two public projects. HANO and RES properties. A group of soil samples The results of Survey 2 shows a significant collected in the early 1990s were initially assigned to difference with Florida exhibiting less soil-Pb than the Fischer housing properties; however, when the C.J Peete properties (P-value = 2.9 · 103); the sample addresses were entered and verified in our amount of Pb that has accumulated is significantly GIS, the locations were not within the correct census different although the age of construction is the tracts. Therefore, Fischer was not collected in Survey same. 1. For most (8 of 9) HANO properties listed in The second case is of HANO properties that Table 2 the exact P-values are larger than 0.05 were constructed in mid-1960, Fischer and Guste. indicating no significant differences when compared Using the same logic that age of construction is a with the RES (r) properties. In Survey 1 (Table 2), surrogate for the amount of risk to Pb-based paint, only one HANO property St. Thomas (STH), with an one might expect the same amount of Pb in the exact P-value of 9.3 · 104, indicates significant environment of both of these public housing differences in soil-Pb compared with the RES properties. Survey 2 data of these HANO properties properties. In this case the amount of soil-Pb is shown in Table 1 and indicates that Guste, accumulated on the HANO properties was less than located in the CORE of New Orleans, contains the amount of soil-Pb present on RES properties. significantly more soil-Pb than the Fischer property Except for St. Thomas (STH), the CORE HANO soil- located in the OUTER area of New Orleans (P- Pb appears similar to soil-Pb on the RES properties. value = 4.3 · 105). Because they differ so mark- Survey 2 results of HANO and RES soil-Pb are edly, age of construction appears to play a small given in Table 3. In Survey 2, the field collection was role in the quantity of Pb that has accumulated in more accurate and occurred in all of the census tracts. soils of these two sets of HANO properties. More than half (7 of 10) of the HANO public Therefore, another source of Pb appears to play a housing, Florida (FLO), Desire (DES), Fischer (FIS), larger role in contaminating the environment of Lafitte (LAF), Guste (GUS), C.J. Peete (CJP), and St. HANO properties that were constructed at the same Thomas (STH) had significantly different amounts time. (P-value less than 0.05) of soil-Pb on them compared Table 1 Evaluation of the age of HANO development as a factor in the amount of lead in the environment. MRPP was employed for P-values Group Min 25% Median 75% Max N P-value Comparison of CORE and OUTER HANO: built in the 1940s, expanded in the 1950s FLO2Pb 32 47 81 107 172 21 2.9 · 103 CJP2Pb 14 39 158 294 981 22 Comparison of CORE and OUTER HANO: built in the mid-1960s FIS2Pb 9.8 23 37 87 279 19 4.3 · 105 GUS2Pb 15.1 153 386 778 6,382 22 123
Environ Geochem Health
Fig. 2 Map of the soil-Pb
footprint of New Orleans
along with the locations of
HANO public housing
properties and the
surrounding residential
(RES) properties [radius of
0.8 km (0.5 mile)]. See
Tables 1–5 for detailed
information about the
quantities of soil-Pb found
on each property
Table 2 Survey 1 of New
Site Min 25% Median 75% Max N MRPP
Orleans completed in 1991.
P-value
Comparison of HANO soil
lead with residential STB1 11 72 135 255 1,316 15 0.70
samples collected within
0.5 miles (0.8 km) of each STB1r 3 24 85 187 1,478 21
HANO property DES1 7 78 230 322 619 13 0.16
DES1r 6 31 99 191 761 23
FLO1 6 91 146 276 464 16 0.64
FLO1r 7 43 119 246 761 29
LAF1 3 103 130 231 303 11 0.11
LAF1r 8 22 295 792 6,007 31
IBE1 19 122 183 514 590 12 0.08
IBE1r 3 264 359 653 1,673 42
BWC1 49 77 293 486 2,157 12 0.36
BWC1r 5 168 532 920 2,261 21
GUS1 147 219 367 1,183 3,485 11 1.00
GUS1r 12 217 449 927 7,435 51
CJP1 54 221 390 622 1,839 10 0.24
CJP1r 31 178 366 935 50,195 71
STH1 30 164 364 1,019 1,743 33 9.3 · 104
STH1r 174 479 934 1,514 33,575 26
with the RES locations within 0.8 km (0.5 miles) of housing project, St. Bernard (STB) had more Pb (not
the public housing properties. Of these seven HANO statistically significant) in its soil than the neighbor-
properties, all of them had significantly less accumu- ing RES (STBr) properties. We note that the STB
lated soil-Pb on them than the RES locations. One housing project is closer to a major highway and
123Environ Geochem Health
Table 3 Survey 2 of New
Site Min 25% Median 75% Max N MRPP
Orleans completed in 2001.
P-value
Comparison of HANO soil
lead with residential STB2 5 82 254 365 1,536 27 0.10
samples collected with
0.8 km (0.5 mile) radius of STB2r 18 55 132 230 1,774 36
each HANO property DES2 32 47 81 107 172 21 3.8 · 103
DES2r 16 72 152 258 1,353 24
FLO2 16 47 84 156 727 19 0.02
FLO2r 31 122 241 438 6,126 30
FIS2 10 23 37 87 279 19 0.04
FIS2r 20 55 77 229 7,633 15
LAF2 3 113 272 458 1,351 22 0.03
LAF2r 9 173 472 1,210 20,210 60
IBE2 18 149 200 309 916 22 0.07
IBE2r 27 121 211 558 14,042 41
BWC2 16 127 271 564 2,052 21 0.07
BWC2r 8 169 632 854 5,128 26
GUS2 15 153 386 778 6,382 22 0.05
GUS2r 14 420 796 2,512 12,648 61
CJP2 14 39 158 294 981 22 2.2 · 104
CJP2r 33 298 734 2,013 15,679 91
STH2 85 229 432 660 3,957 43 5.1 · 103
STH2r 3 511 970 1,593 10,300 36
freeway interchange than the adjoining residential the CORE; in pre-Katrina New Orleans, around 25%
neighborhood. of the inner city children had elevated blood Pb levels
Data from both surveys (Tables 2, 3) show that the (Mielke 2005; Louisiana Office of Public Health, J.
HANO properties had about the same or less Pb Takinaka, 2005, Personal Communication).
accumulation in their soil than the adjacent RES
properties. The only exception was STB but with a P-
value of 0.10, the difference was not significant. Comparison of Surveys 1 and 2 HANO properties
Since the soil-Pb is generally similar at both and RES locations
HANO and adjacent RES properties, we expect that
children’s blood Pb would also be similar at these One advantage of having two surveys at an interval of
two types of properties. This expectation arises from 8 years is that it is possible to consider changes in the
research on the relationship between soil-Pb and amount of Pb contamination that may have taken
blood Pb (Mielke et al. 1997, 1999; Mielke 2002; place in New Orleans over time. Table 4 shows the
Johnson and Bretsch 2002). Soil is both a sink and a trends of the city between Survey 1 completed in
source of lead. During drought when soils are dry and 1992 and Survey 2 completed in 2000. In the OUTER
dusty, blood lead tends to increase; during wet group there are no significant differences (P-value =
periods, when dust is settled, blood lead tends to 0.35) between the two surveys for the HANO public
decrease (Laidlaw et al. 2005). Furthermore, research housing soil-Pb, and there was a moderate increase
has shown that the blood Pb of children living in (P-value = 0.02) in Survey 2 for the RES properties.
inner-city public housing are as elevated as the In the CORE group a similar change took place with
children living in inner-city private housing (Rabito no significant difference (P-values = 0.44) for the
et al. 2003). New Orleans inner-city soil has become HANO properties; however, there was a significant
so severely loaded with Pb that it presents a major increase (P-value = 1.4 · 103) for RES locations.
hazard for children regardless of where they live in Thus, in both the CORE and OUTER groups, HANO
123Environ Geochem Health
Table 4 Comparisons between Survey 1 and Survey 2 for OUTER and CORE census tracts
Group Min 25% Median 75% Max N P-value
OUTHANO1a 6 81 152 276 1,316 44 0.35
OUTHANO2b 5 53 98 263 1,536 67
OUTRES1 3 27 96 191 1,478 51 0.02
OUTRES2 18 103 178 338 6,126 65
COREHANO1 3 132 250 598 3,485 89 0.44
COREHANO2 3 137 284 502 6,382 152
CORERES1 5 191 456 967 50,195 214 1.4 · 103
CORERES2 3 243 707 1,595 20,210 269
a
Fischer is missing from Survey 1
b
Excluded Fischer and Fischer r because FIS was missing in Survey 1
properties remained more or less the same, while the differences between OUTER HANO and OUTER
RES properties showed an increase of soil-Pb from RES locations are either not significant or slightly
1992 to 2000. These results from the small subset of significant, P-values = 0.12 and 0.03, respectively,
data agree with research on the collective trends for for Surveys 1 and 2.
soil metals for the entire database during the interval The differences between OUTER HANO and
of the two surveys (Mielke et al. 2005b). The CORE HANO properties in Surveys 1 and 2 are
increase on RES properties can be explained by the particularly significant (P-values of 8.3 · 104 and
common practice of power sanding during prepara- 9.6 · 106, respectively). Even smaller P-values
tion for repainting old homes a process which (3.3 · 107 and 2.7 · 107, respectively) are found
releases large quantities of Pb (Jacobs et al. 2003; between the data sets for OUTER RES and CORE
Mielke et al. 2001; Mielke et al. 2006b). RES properties. The medians for soil-Pb in
OUTER RES were 96 and 178 mg/kg, respectively,
while the medians of the CORE RES were 456 and
Comparison of the amount of Pb accumulated in 707 for Surveys 1 and 2, respectively. This means
CORE areas compared with OUTER areas of that more than half of the samples on residential
New Orleans properties in the urban CORE were above the U.S.
soil-Pb standard of 400 mg/kg (US EPA). In
The soil-Pb on the HANO and RES properties varies comparison to the soil-Pb standards of
with respect to the general pattern (i.e., red, high and 40150 mg/kg set by other nations, the soils in
blue, low) for soil-Pb in New Orleans are shown in New Orleans are severely contaminated (Mielke
Fig. 2. To test the idea that location is an important 2005; Mielke et al. 2006b).
factor in the quantity of soil-Pb on HANO and RES
properties the combined results were stratified into
CORE or OUTER groups. These results are shown in The soil-Pb footprint of New Orleans
Table 5 and provide a comprehensive evaluation of
the relationships between HANO and RES properties The soil-Pb footprint in both HANO and RES
for CORE and OUTER New Orleans. communities are the result of policy decisions that
The combined results show that HANO properties were made by corporations and government outside
in CORE areas of the city have less soil-Pb than the the control of ordinary citizens, public or private
adjacent RES properties. The difference between entities within New Orleans and other cities (Rosner
CORE HANO and CORE RES properties are signif- and Markowitz 1985). The processes contributing to
icant (P-values 3.9 · 103 and 8.6 · 1010) for the disproportional Pb contamination of the urban
Surveys 1 and 2, respectively. On the other hand, CORE compared to the OUTER areas of the city are
123Environ Geochem Health
Table 5 Results for combined HANO and RES datasets stratified by CORE and OUTER locations
Group Min 25% Median 75% Max N MRPP P-value
CORE1 HANO 2.5 132 250 598 3,485 89 3.9 · 103
CORE1 RES 4.6 191 456 967 50,195 214
CORE2 HANO 3.2 137 284 502 6,382 152 8.6 · 1010
CORE2 RES 2.5 243 707 1,595 20,210 269
OUT1 HANOa 6.2 81 152 276 1,316 44 0.12
OUT1 RES 2.5 27 96 191 1,478 51
OUT2 HANO 4.5 53 98 263 1,536 67 0.03
OUT2 RES 18.3 103 178 338 6,126 65
OUT1 HANOa 6.2 81 152 276 1,316 44 8.3 · 104
CORE1 HANO 2.5 132 250 598 3,485 89
OUT2 HANO 4.5 53 98 263 1,536 67 9.6 · 106
CORE2 HANO 3.2 137 284 502 6,382 152
OUT1 RES 2.5 27 96 191 1,478 51 3.3 · 107
CORE1 RES 4.6 191 456 967 50,195 214
OUT2 RES 18.3 103 178 338 6,126 65 2.7 · 107
CORE2 RES 2.5 243 707 1,595 20,210 269
a
Fischer, in outer New Orleans, is missing from Survey 1
tied to two high production Pb sources, namely, Pb- Conclusions
based paint and Pb additives to gasoline; nationally
these products accounted for about 12 million tons of The major finding of this study is that location of
Pb. Similarly aged HANO properties (i.e., similar Pb public housing projects or adjacent residential prop-
content of paint) have different quantities of soil-Pb erties are within the context of the soil-Pb footprint of
in CORE and OUTER communities of New Orleans; the whole city. The largest accumulation of Pb
what accounts for the soil-Pb differences between occurred within the inner city CORE of New Orleans,
these two areas? One explanation of the soil-Pb and the OUTER communities had a fraction of the
footprint in New Orleans is the dispersal of tetraethyl soil-Pb. In New Orleans, public housing properties
lead (TEL) additives used in gasoline. constructed during the same years have significantly
Controversy surrounded TEL from the beginning larger amounts of soil-Pb in CORE compared with
of its use in the 1920s (Rosner and Markowitz 1985; OUTER locations of the city. The previous use and
Patterson 1980; Lewis 1985; Nriagu 1990). TEL is dispersal of Pb-based paint, especially when it is
related to historic traffic flows and congestion (Rolfe power sanded and released as fine particles of Pb,
and Haney 1975; Mielke et al 1989; Mielke and poses a continuing hazard. However, TEL additives
Reagan 1998). As a result, TEL was disproportion- emitted from traffic was unevenly distributed and
ately dispersed in cities and the main pattern of Pb created the major soil-Pb footprint in New Orleans.
deposition is reflected by the soil-Pb footprint found Thus, the significant differences in soil-Pb between
in New Orleans. The soil-Pb footprint reported for the CORE and OUTER communities can be more
New Orleans, showing an inner-city and outlying satisfactorily explained by TEL than by Pb-based
community difference, is not unique. It has also paint. By any standard, the amount of soil-Pb within
been described for Baltimore, Minneapolis and St. the CORE area, especially on private residential
Paul, Indianapolis, Syracuse, and other cities around properties (present median *707 mg/kg) of New
the globe (Mielke et al. 1983; Mielke et al. 1984; Orleans is excessive. In pre-Katrina New Orleans,
Mielke et al. 1989; Filippelli et al. 2005; Johnson children living in the inner-city exhibited Pb expo-
and Bretsch 2002; Jartun et al. 2003; Ljung et al. sures of epidemic proportions. In order for the
2006). community to be Pb-safe, extensive primary
123Environ Geochem Health
prevention must be taken to protect children from Indianapolis, Indiana, Syracuse, New York and New
exposure to the urban soil-Pb footprint of New Orleans, Louisiana (USA). Environmental Health Per-
spectives, 113(6), 793–800.
Orleans. Landrigan, P. J., Schechter, C. B., Lipton, J. M., Fahs, M. C., &
Schwartz, J. (2002). Environmental pollutants and disease
Acknowledgments Funding for the soil surveys was in American children: Estimates of morbidity, mortality,
provided by grants to Xavier University from the Louisiana and costs for lead poisoning, asthma, cancer, and devel-
Educational Quality and Science Fund (LEQSF) and an opmental disabilities. Environmental Health Perspectives,
Agency for Toxic Substances and Disease Registry/Minority 110, 721–728.
Health Professional Foundation cooperative agreement to Lewis, J. (1985). Lead poisoning: A historical perspective.
Xavier University of Louisiana. A pilot project to test the EPA Journal, May 1985 http://www.epa.gov/history/
impact of emplacing clean soil on contaminated property was topics/perspect/lead.htm (Accessed February 2, 2007).
funded by a U.S. Housing and Urban Development Lead Ljung, K., Selinus, O., Otabbong, E., & Berglund, M. (2006).
Technical Study to Xavier University of Louisiana. The views Metal and arsenic distribution in soil particle sizes rele-
expressed in this paper are those of the authors and do not vant to soil ingestion by children. Applied Geochemistry,
necessarily reflect the positions or policies of the funding 21(9), 1613–1624.
agencies. Mielke, H. W. (1994). Lead in New Orleans soils: New images
of an urban environment. Environmental Geochemistry
and Health, 16(3/4), 123–128.
Mielke, H. W. (1999). Lead in the inner-cities. American Sci-
References entist, 87, 62–73.
Mielke, H. W. (2002). Research ethics in pediatric environ-
Blossom (2005, August) update. Accessed April 10, 2006, mental health: Lessons from lead. Neurotoxicology and
from Teratology, 24(4), 467–469.
http://www.fort.usgs.gov/products/software/blossom/ Mielke, H. W. (2005). Lead’s toxic urban legacy and children’s
blossom.asp. health. Geotimes, 50(5), 22–26.
Brown, M. J., & Jacobs, D. E. (2006). Correspondence: Mielke, H. W., Adams, J. L., Reagan, P. L., & Mielke, P. W.,
Sources of blood lead in children. Environmental Health Jr. (1989). Soil-dust lead and childhood lead exposure as a
Perspectives, 114(1), A18–A19. function of city size and community traffic flow: The case
Canfield, R. L., Henderson, C. R., Jr., Cory-Slechta, D. A., for lead contaminated soil abatement in Minnesota. In
Cox, C., Jusko, T. A., & Lanphear, B. P. (2003). Intel- Lead in soil: Issues and guidelines (pp. 253–271).
lectual impairment in children with blood lead Northwood, Britain: Science Reviews, Ltd. (ISBN 0-
concentrations below 10 lg per deciliter. New England 905927-92-3.).
Journal of Medicine, 348, 1517–1526. Mielke, H. W., Anderson, J. C., Berry, K. J., Mielke, P. W., Jr.,
Clark, S., Menrath, W., Chen, M., Succop, P., Bornschein, R., Chaney, R. L., & Leech, M. (1983). Lead concentrations
Galke, W., & Wilson, J. (2004). The influence of exterior in inner-city soils as a factor in the child lead problem.
dust and soil lead on interior dust lead levels in housing American Journal of Public Health, 73(12), 1366–1369.
that had undergone lead-based paint hazard control. Mielke, P. W., & Berry, K. J. (2007). Permutation methods: A
Journal of Occupational and Environmental Hygiene, 1, distance function approach (2nd ed.). New York:
273–282. Springer-Verlag.
Filippelli, G. M., Laidlaw, M., Latimer, J., & Raftis R. (2005). Mielke, H. W., Berry, K. J., Mielke, P. W., Powell, E. T., &
Urban lead poisoning and medical geology: An unfinished Gonzales, C. R. (2005a). Multiple metal accumulation as
story. Geological Society of America Today, 15, 4–7. a factor in learning achievement within various New
HOPE VI Demolition and Revitalization Grants. http://www. Orleans communities. Environmental Research, 97(1),
federalgrantswire.com/demolition_and_revitalization_of_ 67–75.
severely_distressed_public_housing.html (accessed April Mielke, H. W., Blake, B., Burroughs, S., & Hassinger, N.
5, 2006). (1984). Urban lead levels in Minneapolis: The case of the
Jacobs, D., Mielke, H. W., & Pavur, N. (2003). The high cost Hmong children. Environmental Research, 34, 64–76.
of improper removal of lead-based paint from housing: A Mielke, H. W., Dugas, D., Mielke, P. W., Smith, K. S., Smith,
case report. Environmental Health Perspectives, 111, S. L., & Gonzales, C. R. (1997). Associations between
185–186. soil lead and childhood blood lead in urban New Orleans
Jartun, M., Ottesen, R. T., & Steinnes, E. (2003). Urban soil and rural Lafourche Parishes of Louisiana USA. Envi-
pollution and the playfields of small children. Journal ronmental Health Perspectives, 105, 950–954.
Physique IV France, 107, 671–674. Mielke, H. W., Gonzales, C., Powell, E., & Mielke, P. W., Jr.
Johnson, D. S., & Bretsch, J. K. (2002). Soil lead and chil- (2005b). Changes of multiple metal accumulation (MMA)
dren’s blood lead levels in Syracuse, NY, USA. in New Orleans soil: Preliminary evaluation of differences
Environmental Geochemistry and Health, 24(4), 373–385. between Survey I (1992) and Survey II (2000). Interna-
Laidlaw, M. A. S., Mielke, H. W., Filippelli, G. M., Johnson, tional Journal of Environmental Research and Public
D. L., & Gonzalez, C. R. (2005). Seasonality and chil- Health, 2(2), 84–90.
dren’s blood lead levels: Developing a predictive model Mielke, H. W., Gonzales, C. R., Powell, E. T., Shah, A., &
using climatic variables and blood lead data from Mielke, P. W., Jr. (2002). Natural and anthropogenic
123Environ Geochem Health
processes that concentrate Mn in rural and urban envi- Nevin, R. (2000). How lead exposure relates to temporal
ronments of the lower Mississippi River delta. changes in IQ, violent crime, and unwed pregnancy.
Environmental Research, 90(2), 157–168. Environmental Research, 83, 1–22.
Mielke, H. W., Gonazales, C. R., Smith, C. R., & Mielke, P. Nriagu, J. O. (1990). The rise, fall of leaded gasoline. Science
W., Jr. (1999). The urban environment and children’s of the Total Environment, 92, 1–28.
health: soils as an integrator of lead, zinc, and cadmium in Patterson, C. C. (1980). An alternative perspective—lead pol-
New Orleans, Louisiana, USA. Environmental Research, lution in the human environment: Origin, extent, and
81, 117–129. significance. In Lead in the human environment (pp. 265–
Mielke, H. W., Gonzales, C. R., Smith, M. K., & Mielke, P. 349). Washington, DC: National Research Council,
W., Jr. (2000). Quantities and associations of lead, zinc, National Academy of Sciences. Nation Academy Press.
cadmium, manganese, chromium, nickel, vanadium, and Rabito, F. A., Shorter, C., & White, L. E. (2003). Lead levels
copper in fresh Mississippi delta alluvium and New among children who live in public housing. Epidemiology,
Orleans alluvial soils. Science of the Total Environment, 14(3), 263–268.
246, 249–259. Reagan, P. L. & Silbergeld, E. K. (1989). Establishing a health
Mielke, H. W., Powell, E. T., Gonzales, C. R., & Mielke, P. based standard for lead in residential soils. In D. H.
W., Jr. (2006b). Hurricane Katrina’s impact on New Hemphill & C. R. Cothern (Eds.), Trace substances in
Orleans soils treated with low lead Mississippi River environmental health, XXIII, (Suppl. to Vol. 12) Envi-
alluvium. Environmental Science and Technology 40, ronmental geochemistry and health, pp. 199–238.
7623–7628. Rolfe, G. L., & Haney, A. (1975). An ecosystem analysis of
Mielke, H. W., Powell, E. T., Gonzales, C. R., Mielke, P. W., environmental contamination by lead. Urbana, Illinois:
Jr., Ottesen, R. T., & Langedal, M. (2006a). New Orleans Institute for Environmental Studies, University of Illinois
soil lead (Pb) cleanup using Mississippi River alluvium: at Urbana-Champaign.
Need, feasibility and cost. Environmental Science and Rosner, D., & Markowitz, G. (1985). A ‘gift of god’?: the public
Technology, 40(8), 2784–2789. health controversy over leaded gasoline during the 1920s.
Mielke, H. W., Powell, E., Shah, A., Gonzales, C., & Mielke, American Journal of Public Health, 75(4):344–352.
P. W. (2001). Multiple metal contamination from house Sayer, J. W., Charnery, E., Vostal, J., & Pless, I. B. (1974).
paints: Consequences of power sanding and paint scraping House and hand dust as a potential source of childhood
in New Orleans. Environmental Health Perspectives, 109, lead exposure. American Journal of Disabled Children,
973–978. 127, 167–170.
Mielke, H. W., & Reagan, P. L. (1998). Soil is an important Tsaih, S. W., Korrick, S., Schwartz, J., Amarasiriwardena, C.,
pathway of human lead exposure. Environmental Health Aro, A., Sparrow, D., & Hu, H. (2004). Lead, diabetes,
Perspectives, 106, 217–229. hypertension, and renal function: The normative aging
Needleman, H. L., McFarland, C., Ness, R. B., Fienberg, S. E., study. Environmental Health Perspectives, 112(11),
& Tobin, M. J. (2002). Bone lead levels in adjudicated 1178–1182.
delinquents. A case control study. Neurotoxicology and U.S. EPA. (2001). Lead, identification of dangerous levels of lead,
Teratology, 24, 711–717. final rule. 40CFR745. Fed. Reg. 2001, 66, 6763–6765.
123You can also read
