Development of biomonitoring equivalents for barium in urine and plasma for interpreting human biomonitoring data

Abstract

The objectives of the present work were: (1) to assemble population-level biomonitoring data to identify the concentrations of urinary and plasma barium across the general population; and (2) to derive biomonitoring equivalents (BEs) for barium in urine and plasma in order to facilitate the interpretation of barium concentrations in the biological matrices. In population level biomonitoring studies, barium has been measured in urine in the U.S. (NHANES study), but no such data on plasma barium levels were identified. The BE values for plasma and urine were derived from U.S. EPA's reference dose (RfD) of 0.2 mg/kg bw/d, based on a lower confidence limit on the benchmark dose (BMDL) of 63 mg/kg bw/d. The plasma BE (9 μg Ba/L) was derived by regression analysis of the near-steady-state plasma concentrations associated with the administered doses in animals exposed to barium chloride dihydrate in drinking water for 2-years in a NTP study. Using a human urinary excretion fraction of 0.023, a BE for urinary barium (0.19 mg/L or 0.25 mg/g creatinine) was derived for US EPA's RfD. The median and the 95 percentile barium urine concentrations of the general population in U.S. are below the BE determined in this study, indicating that the population exposure to inorganic barium is expected to be below the exposure guidance value of 0.2 mg/kg bw/d.

Safety aspects of stingless bee pot-pollen from the Philippines

“…Ba toxicity depends on its Safety aspects of stingless bee pot-pollen from the Philippines Die Bodenkultur: Journal of Land Management, Food and Environment 71 (2) 2020 solubility and its main target in humans is the cardiovascular system. However, there is only limited data about its neurological and reproductive toxicity (Poddalgoda et al, 2017). Nickel (Ni) and Chromium (Cr) concentrations were partially in accordance to those reported by Morgano et al (2010), but were generally lower compared to other studies (Yang et al, 2013;Kostić et al, 2015;Sattler et al, 2016;Kalaycıoğlu et al, 2017).…”

Biomonitoring of Metals in Children Living in an Urban Area and Close to Waste Incinerators

“…Ba is not essential in human nutrition, but, as mainly suggested by animal studies, health effects secondary to chronic Ba exposure are possible in humans, although results from epidemiologic studies are still scarce [90], as are biomonitoring reports [91]. The main routes of nonoccupational human exposure to Ba are the ingestion of contaminated food and/or water [90].…”

Teeth reveal juvenile diet, health and neurotoxicant exposure retrospectively: What biological rhythms and chemical records tell us

“…[32][33][34] Considerations of non-essential metals further illustrate the complex relationship between elemental chemistry and physiology. Barium (Ba) can be absorbed via GI uptake with lethal effect when bound to soluble salts, [35,36] but when bound to sulfate it forms insoluble barium sulfate and is excreted. In this form it is considered safe for use in clinical X-ray imaging as a GI contrast agent.…”

“…[21,65,79] Our model (Figure 2A) was predicated on the ideas that most supplemental foods contain less bioavailable barium than milk, as is the case with Ca, [80] and that the absorption of barium decreases with age. [35,43] Physiological F I G U R E 4 Elemental matching process allowing registration of teeth in a ∼5-6 year-old wild baboon (Papio hamadryas) juvenile (73436) originally detailed in ref [55] . (A) Two lead exposure "events" are evident in a developing lower canine that correspond to elevated lead bands in the M1 (single band in root), second molar (M2: initial band at end of crown formation, second band in the developing root), and third molar (M3: single band in developing crown).…”