Evaluation of trace-element contamination from serum collection tubes used by the California Biobank Program.

BACKGROUND: Serum samples archived by the California Biobank Program (CBP) can be a valuable resource to researchers with multiple benefits: affordability, relatively large sample sizes, and racial and geographical representativeness. However, there has been little attention given to the reliability of CBP samples for trace-element analysis. The objectives of this study are to estimate the contamination levels from the serum separation tubes (SST, BD 367983) utilized by the CBP for 13 trace elements (Cr, Mn, Co, As, Se, Sr, Mo, Cd, Sb, Hg, Tl, Pb and U) and to evaluate the feasibility of the use of CBP serum samples for biomonitoring trace elements in human body. METHODS: Serum separation tubes were tested using deionized (DI) water and whole blood and compared with two alternative sampling devices, plasma separation tubes (PST, BD 365047) and acid-cleaned blood tubes (ABT, BD 367856). RESULTS AND CONCLUSIONS: The leaching tests for SSTs with DI water demonstrated that detectable levels of Cr, Mn, Co, Sr, Sb, Pb and U were measured, while Sb was elevated. Tests of PSTs also revealed contamination of Mn, Co, Sr and Sb, with Co and Sr being much higher than those found from SSTs. As a more direct approach to estimate trace element contamination, a 45-day time series was conducted using human blood. The differences in elemental concentrations leached into serum/plasma was not considerable between the three types of sampling tubes for Cr, As, Se, Mo, Cd, Hg and Tl. However, SSTs had far greater concentrations than the ABTs for Mn, Co, Sr, Sb and U. For Co and Sr, the PSTs had higher concentrations throughout the experiment than both ABTs and SSTs. Pb showed lower concentrations from the PSTs than the other tubes; we speculate this may be due to re-suspension of settled cellular materials that are elevated in Pb, or re-dissolution of Pb from these materials. Trace-element measurements from 200 samples archived by the CBP using SSTs suggest that SST contamination was negligible for Se and Mo. For Mn, As, Sr, Cd and Hg, based on our leaching results, only a fraction of these samples had considerably high concentrations (e.g., > 10×) compared to the contamination from the SST. For Cr, Co, Sb, Tl, Pb and U, analyte levels were too low in most samples compared to the contamination from the SSTs. Our study also demonstrated that the PSTs could be a "cleaner" alternative to SSTs for analytes such as Cr, As, Cd, Hg, Tl, Pb and U.

Heavy Metals in California Women Living in a Gold Mining-Impacted Community.

Gold mining activities occurred throughout the foothills of the Sierra Nevada Mountains in California, leaving behind persistent toxic contaminants in the soil, dust, and water that include arsenic and cadmium. Despite a high level of concern among local residents about potential exposure and high breast cancer rates, no biomonitoring data has been collected to evaluate the levels of heavy metals. We conducted a study to characterize the urinary levels of heavy metals among women in this region by working with the community in Nevada County. Sixty women provided urine samples and completed a questionnaire. We examined levels of arsenic, cadmium, and other metals in relation to the length of residency in the area, age, dietary factors, recreational activities, and smoking. We compared urinary metal levels in participants to levels in the United States National Health and Nutrition Examination Survey (NHANES). Overall, study participants had higher urinary levels of arsenic than women in the national sample. Cadmium levels were similar to the national average, although they were elevated in women ≥35 years who had lived in the region for 10 years or more. Arsenic levels were higher among women who smoked, ate fish, ate home-grown produce, and who reported frequent hiking or trail running, although these differences were not statistically significant. This study established a successful community-research partnership, which facilitated community dialogue about possible human health consequences of living in a mining-impacted area.

Lead exposure during childhood and subsequent anthropometry through adolescence in girls.

INTRODUCTION: Cross-sectional studies suggest that postnatal blood lead (PbB) concentrations are negatively associated with child growth. Few studies prospectively examined this association in populations with lower PbB concentrations. We investigated longitudinal associations of childhood PbB concentrations and subsequent anthropometric measurements in a multi-ethnic cohort of girls. METHODS: Data were from The Breast Cancer and the Environment Research Program at three sites in the United States (U.S.): New York City, Cincinnati, and San Francisco Bay Area. Girls were enrolled at ages 6-8 years in 2004-2007. Girls with PbB concentrations collected at ≤10 years old (mean 7.8 years, standard deviation (SD) 0.82) and anthropometry collected at ≥3 follow-up visits were included (n = 683). The median PbB concentration was 0.99 µg/d (10th percentile = 0.59 µg/dL and 90th percentile = 2.00 µg/dL) and the geometric mean was 1.03 µg/dL (95% Confidence Interval (CI): 0.99, 1.06). For analyses, PbB concentrations were dichotomized as <1 µg/dL (n = 342) and ≥1 µg/dL (n = 341). Anthropometric measurements of height, body mass index (BMI), waist circumference (WC), and percent body fat (%BF) were collected at enrollment and follow-up visits through 2015. Linear mixed effects regression estimated how PbB concentrations related to changes in girls' measurements from ages 7-14 years. RESULTS: At 7 years, mean difference in height was -2.0 cm (95% CI: -3.0, -1.0) for girls with ≥1 µg/dL versus <1 µg/dL PbB concentrations; differences persisted, but were attenuated, with age to -1.5 cm (95% CI: -2.5, -0.4) at 14 years. Mean differences for BMI, WC, and BF% at 7 years between girls with ≥1 µg/dL versus <1 µg/dL PbB concentrations were -0.7 kg/m2 (95% CI: -1.2, -0.2), -2.2 cm (95% CI: -3.8, -0.6), and -1.8% (95% CI: -3.2, -0.4), respectively. Overall, these differences generally persisted with advancing age and at 14 years, differences were -0.8 kg/m2 (95% CI: -1.5, -0.02), -2.9 cm (95% CI: -4.8, -0.9), and -1.7% (95% CI: -3.1, -0.4) for BMI, WC, and BF%, respectively. CONCLUSIONS: These findings suggest that higher concentrations of PbB during childhood, even though relatively low by screening standards, may be inversely associated with anthropometric measurements in girls.

Unintentional and Sequential Lead Exposure from a Ceramic Mug and Maca (Lepidium meyenii).

Although the incidence of lead poisoning has decreased in the USA over the last 30 years, human exposures to lead-containing products are still reported. We present a case of unintentional lead exposure from a store-bought ceramic mug and a nutritional supplement. A 32-year-old female was found to have a whole blood lead concentration of 44 µg/dL. Evaluation of her home, occupation, and hobbies initially did not identify a source of lead exposure. Further investigation revealed that the likely etiology of the exposure was lead leaching from a ceramic mug used by the patient to drink hot lemon water while she was pregnant. She stopped drinking from the mug and her blood lead levels decreased, but increased a year later after she began to ingest a maca root powder supplement. Upon discontinuation of maca root powder ingestion, her blood lead levels decreased further. Over time, the acidity and heat of the hot lemon water used in the ceramic mug enhanced the breakdown of its leaded glaze. Maca powder, which is available as a nutritional supplement and is used to treat fatigue and enhance fertility, may contain lead and other minerals. Consumers, particularly women of childbearing age, and their physicians should be aware that imported products available from commercial retailers and internet vendors may contain significant amounts of lead.

Environmental Chemicals in an Urban Population of Pregnant Women and Their Newborns from San Francisco.

Exposures to environmental pollutants in utero may increase the risk of adverse health effects. We measured the concentrations of 59 potentially harmful chemicals in 77 maternal and 65 paired umbilical cord blood samples collected in San Francisco during 2010-2011, including polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), polybrominated diphenyl ethers (PBDEs), hydroxylated PBDEs (OH-PBDEs), and perfluorinated compounds (PFCs) in serum and metals in whole blood. Consistent with previous studies, we found evidence that concentrations of mercury (Hg) and lower-brominated PBDEs were often higher in umbilical cord blood or serum than in maternal samples (median cord:maternal ratio > 1), while for most PFCs and lead (Pb), concentrations in cord blood or serum were generally equal to or lower than their maternal pair (median cord:maternal ratio ≤ 1). In contrast to the conclusions of a recent review, we found evidence that several PCBs and OCPs were also often higher in cord than maternal serum (median cord:maternal ratio > 1) when concentrations are assessed on a lipid-adjusted basis. Our findings suggest that for many chemicals, fetuses may experience higher exposures than their mothers and highlight the need to characterize potential health risks and inform policies aimed at reducing sources of exposure.

Development and validation of a simple and robust method for arsenic speciation in human urine using HPLC/ICP-MS.

In order to better distinguish the different toxic inorganic and organic forms of arsenic (As) exposure in individuals, we have developed and validated a simple and robust analytical method for determining the following six As species in human urine: arsenous (III) acid (As-III), As (V) acid, monomethylarsonic acid, dimethylarsinic acid, arsenobetaine (AsB), and arsenocholine. In this method, human urine is diluted using a pH 5.8 buffer, separation is performed using an anion exchange column with isocratic HPLC, and detection is achieved using inductively coupled plasma-MS. The method uses a single mobile phase consisting of low concentrations of both phosphate buffer (5 mM) and ammonium nitrate salt (5 mM) at pH 9.0; this minimizes the column equilibration time and overcomes challenges with separation between AsB and As-III. In addition, As-III oxidation is prevented by degassing the sample preparation buffer at pH 5.8, degassing the mobile phase online at pH 9.0, and by the use of low temperature (-70 °C) and flip-cap airtight tubes for long term storage of samples. The method was validated using externally provided reference samples. Results were in agreement with target values at varying concentrations and successfully passed external performance test criteria. Internal QC samples were prepared and repeatedly analyzed to assess the method's long-term precision, and further analyses were completed on anonymous donor urine to assess the quality of the method's baseline separation. Results from analyses of external reference samples agreed with target values at varying concentrations, and results from precision studies yielded absolute CV values of 3-14% and recovery from 82 to 115% for the six As species. Analysis of anonymous donor urine confirmed the well-resolved baseline separation capabilities of the method for real participant samples.

Biomonitoring in California firefighters: metals and perfluorinated chemicals.

OBJECTIVE: To assess California firefighters' blood concentrations of selected chemicals and compare with a representative US population. METHODS: We report laboratory methods and analytic results for cadmium, lead, mercury, and manganese in whole blood and 12 serum perfluorinated chemicals in a sample of 101 Southern California firefighters. RESULTS: Firefighters' blood metal concentrations were all similar to or lower than the National Health and Nutrition Examination Survey (NHANES) values, except for six participants whose mercury concentrations (range: 9.79 to 13.42 µg/L) were close to or higher than the NHANES reporting threshold of 10 µg/L. Perfluorodecanoic acid concentrations were elevated compared with NHANES and other firefighter studies. CONCLUSIONS: Perfluorodecanoic acid concentrations were three times higher in this firefighter group than in NHANES adult males. Firefighters may have unidentified sources of occupational exposure to perfluorinated chemicals.