Henry M. Spliethoff

Lead (Pb) and other metals in New York City community garden soils: factors influencing contaminant distributions.

Urban gardens provide affordable fresh produce to communities with limited access to healthy food but may also increase exposure to lead (Pb) and other soil contaminants. Metals analysis of 564 soil samples from 54 New York City (NYC) community gardens found at least one sample exceeding health-based guidance values in 70% of gardens. However, most samples (78%) did not exceed guidance values, and medians were generally below those reported in NYC soil and other urban gardening studies. Barium (Ba) and Pb most frequently exceeded guidance values and along with cadmium (Cd) were strongly correlated with zinc (Zn), a commonly measured nutrient. Principal component analysis suggested that contaminants varied independently from organic matter and geogenic metals. Contaminants were associated with visible debris and a lack of raised beds; management practices (e.g., importing uncontaminated soil) have likely reduced metals concentrations. Continued exposure reduction efforts would benefit communities already burdened by environmental exposures.

Concentrations of lead, cadmium and barium in urban garden-grown vegetables: The impact of soil variables

Paired vegetable/soil samples from New York City and Buffalo, NY, gardens were analyzed for lead (Pb), cadmium (Cd) and barium (Ba). Vegetable aluminum (Al) was measured to assess soil adherence. Soil and vegetable metal concentrations did not correlate; vegetable concentrations varied by crop type. Pb was below health-based guidance values (EU standards) in virtually all fruits. 47% of root crops and 9% of leafy greens exceeded guidance values; over half the vegetables exceeded the 95th percentile of market-basket concentrations for Pb. Vegetable Pb correlated with Al; soil particle adherence/incorporation was more important than Pb uptake via roots. Cd was similar to market-basket concentrations and below guidance values in nearly all samples. Vegetable Ba was much higher than Pb or Cd, although soil Ba was lower than soil Pb. The poor relationship between vegetable and soil metal concentrations is attributable to particulate contamination of vegetables and soil characteristics that influence phytoavailability.

Exploratory assessment of perfluorinated compounds and human thyroid function.

Thyroid hormones play critical roles in human neurodevelopment and adult neurocognitive function. Persistent organohalogen pollutants, such as perfluorinated compounds (PFCs), may interfere with thyroid homeostasis and thus exposures to these compounds might represent risk factors for neurologic and cognitive abnormalities. In this study, serum specimens collected from thirty-one licensed anglers in New York State were analyzed for levels of thyroid stimulating hormone (TSH), free thyroxine (FT(4)), perfluorodecanoic acid (PFDA), perfluorononanoic acid (PFNA), perfluoroheptanoic acid (PFHpA), perfluorohexanesulfonate (PFHxS), perfluorooctanoic acid (PFOA), perfluorooctanesulfonate (PFOS), perfluorooctanesulfonamide (PFOSA), and perfluoroundecanoic acid (PFUnDA). PFOS and PFOA occurred in the highest concentrations with geometric means of 19.6 ng/mL (95% CI 16.3-23.5) and 1.3 ng/mL (95% CI 1.2-1.5), respectively. In a cross-sectional analysis, no statistically significant associations were detected for PFCs, or their sum, with TSH or FT(4) at alpha=0.05. However, post hoc power analyses, though limited, suggested that moderate increases in sample size, to 86 and 129 subjects, might facilitate 80% power to detect statistically significant associations for FT(4) and PFDA (beta=0.09) and PFUnDA (beta=0.08), respectively. The consumption of sportfish may have contributed to PFDA (r=0.52, P=0.003) and PFUnDA (r=0.40, P=0.025) levels. This preliminary study does not indicate associations between non-occupational PFCs exposures and thyroid function. However, the possibility for weak associations for FT(4) with PFDA and PFUnDA, PFCs measured in low concentrations, is raised. Given the ubiquity of PFCs in the environment and the importance of thyroid function to neurodevelopmental and neurocognitive endpoints, a confirmatory study is warranted.

Environmental exposure to PBDEs and thyroid function among New York anglers

Experimental studies suggest that polybrominated diphenyl ethers (PBDEs) can influence thyroid function, although the few human studies reported provide little support for this premise. Great Lakes sportfish anglers represent a population with potentially elevated dietary exposure to PBDEs due to the lipophilic nature of these compounds. Thirty-six licensed anglers who participated in the New York State Angler Cohort Study donated blood and completed questionnaires regarding demographic, clinical and sportfish consumption information. Archived blood specimens were analyzed for thyroid stimulating hormone, total and free thyroxine, total triiodothyronine, total serum lipids and nine PBDE congeners. PBDE congener profiles were dominated by BDE-47 (median=7.9ng/g lipids), BDE-153, and BDE-99 (medians=1.8ng/g lipids). No significant associations were observed between congeners, or their sum (ΣPBDEs), and thyroid function. However, the possibility of a positive association between ΣPBDEs and fT(4), detectable with an approximate ninefold increase in sample size, suggests that additional studies are needed.

Concentrations of polycyclic aromatic hydrocarbons in New York City community garden soils: Potential sources and influential factors

A total of 69 soil samples from 20 community gardens in New York City (New York, USA) were collected and analyzed for 23 polycyclic aromatic hydrocarbons (PAHs) and black carbon. For each garden, samples were collected from nongrowing areas (non-bed) and from vegetable-growing beds, including beds with and without visible sources of PAHs. The sum of the US Environmental Protection Agencys 16 priority PAHs ranged up to 150 mg/kg, and the median (5.4 mg/kg) and mean (14.2 mg/kg) were similar to those previously reported for urban areas in the northeast United States. Isomer ratios indicated that the main sources of PAHs were petroleum, coal, and wood combustion. The PAH concentrations were significantly and positively associated with black carbon and with modeled air PAH concentrations, suggesting a consistent relationship between historical deposition of atmospheric carbon-adsorbed PAHs and current PAH soil concentrations. Median PAH soil concentration from non-bed areas was higher (7.4 mg/kg) than median concentration from beds in the same garden (4.0 mg/kg), and significantly higher than the median from beds without visible sources of PAHs (3.5 mg/kg). Median PAH concentration in beds from gardens with records of soil amendments was 58% lower compared with beds from gardens without those records. These results suggest that gardening practices in garden beds without visible sources of PAHs contribute to reduce PAH soil concentrations.

Exploratory assessment of sportfish consumption and polybrominated diphenyl ether exposure in New York State anglers

A cross-sectional study was conducted to examine the influence of sportfish consumption on body burden of nine polybrominated diphenyl ether (PBDE) congeners in 36 New York State (NYS) anglers. Participating anglers who had previously reported consuming sportfish from Lake Ontario and its tributaries were found to have significantly higher blood plasma levels of BDE-28, BDE-47, BDE-99, BDE-100, and the sum of measured PBDE congeners (SigmaPBDE), than anglers who had previously reported no consumption of sportfish from these waters. Bivariate analysis was used to evaluate potential dietary predictors of PBDE plasma levels, including indicators of consumption of sportfish, as well as commercial fish, wild waterfowl, dairy products, and beef. The number of years of reported consumption of Lake Ontario sportfish between 1980 and 1990 was found to be correlated with plasma levels of BDE-47, BDE-85, BDE-99, BDE-100, BDE-153, BDE-154, and SigmaPBDE. The number of meals, eaten in the year prior to study participation, of Lake Ontario sportfish species known to have high levels of other persistent organic pollutants (POPs) was correlated with plasma levels of BDE-28, BDE-47, BDE-85, BDE-99, BDE-100, BDE-154, and SigmaPBDE. Multiple linear regression revealed that the number of years consuming Lake Ontario sportfish between 1980 and 1990, after adjusting for plasma lipids, was a weak, but statistically significant, predictor of SigmaPBDE plasma levels (beta=0.130, 95% CI: 0.007-0.254). These results suggest that sportfish consumption can contribute measurably to PBDE body burden in NYS anglers, although there are likely to be additional, more significant, sources of exposure.

A Comparison of Screening Tests for Soil Pb.

Abstract Soil has been identified as a significant source of lead (Pb) exposure for both children and adults. Therefore, identifying possibly contaminated soils by soil testing is important to protect public health. Soil Pb test results are usually reported as total Pb (in milligrams per kilogram), carried out using a concentrated nitric acid (HNO3) digestion procedure by hot plate (Environmental Protection Agency (EPA) method 3050) or microwave (EPA method 3051) followed by inductively coupled plasma atomic emission spectrometry to determine total Pb in the digest. However, this procedure is both time consuming and expensive, sometimes costing homeowners and gardeners more than

A preliminary study of temporal differences in serum concentrations of perfluoroalkyl acids, among New York anglers, in the absence of known changes in manufacturing practices.

50 per sample. To make soil Pb testing more economically accessible to homeowners and gardeners, several university soil-testing laboratories offer less expensive screening tests designed to estimate total soil Pb. The first objective of this study was to compare three commonly used screening tests, modified Morgan, Mehlich 3, and 1 M HNO3, with the standard total Pb testing method (EPA method 3051) to find which extractant is the most reliable predictor of total Pb. The second objective was to investigate the effect that different degrees of soil grinding have on the total Pb test and the extracted Pb concentration measured from the 1-M HNO3 test. Results indicate that the strongest predictor of total Pb is 1 M HNO3 followed by Mehlich 3 and modified Morgan, and that thorough grinding is necessary if using less than 5 g of soil in a Pb test to adequately homogenize Pb-contaminated samples and achieve acceptable testing reproducibility.

Use of Newborn Screening Program Blood Spots for Exposure Assessment: Declining Levels of Perfluorinated Compounds in New York State Infants

Perfluorinated compounds have been manufactured in large quantities and used in myriad industrial processes and commercial applications. The aim of this preliminary study was to generate hypotheses with regard to differences in body burdens of perfluoroalkyl acids, among a sub-sample of participants from the New York State Angler Cohort Study, over a time interval during which no known substantial changes occurred in US manufacturing practices or commercial use. Paired serum specimens, collected from 15 subjects in 1993–1994 (time 1), and in 1995–1997 (time 2), with a minimum interval of 2.5 years, were assayed for PFDA, PFHpA, PFHxS, PFNA, PFOA, PFOS, PFOSA and PFUnDA using HPLC with ES-MS/MS. By subject, differences in concentrations between time 1 and time 2 were estimated, employing paired t-tests, correlations, and multivariable linear regression to accommodate heterogeneity in duration between specimens, and in time 1 concentrations. A statistically significant (P < 0.05) adjusted mean decrease of 0.16 ng mL−1 (18.8%) between time 1 and 2 was detected for PFNA, and an adjusted mean increase of 0.54 ng mL−1 (56.8%) was detected for PFOA. The results of this study may be indicative of short-term changes in human body burdens of PFNA and PFOA in association with local exposure sources.