Multielemental bioimaging of tissues in children's environmental health research

Abstract

Purpose of review Metals play major roles in children's health and are associated with negative health outcomes via deficiency, overload or toxicity. Constantly evolving analytical technology can provide new insight into how metal metabolism and exposure biology are intertwined in a range of biological matrices. Recent findings Exposure can occur prenatally as many metals cross the placental barrier. The placenta is permeable to many metal species, some through tightly regulated transporters, and others because of a limited capacity for detoxification. Post-birth, metal exposure continues to exert long-term health effects, ranging from exposure to exogenous heavy metals, such as lead, to overload of otherwise essential metals, including manganese. Increasing evidence supports the existence of critical developmental windows when susceptibility to toxicants and nutritional deficiencies is highest. Elemental imaging technology provides micro-spatial information on metal uptake and retention across tissue architecture, which provides important insights into exposure and biologic response. Summary Imaging the spatial distribution of elements, both essential and toxic, provides information that bulk measures cannot, including cell-specific distributions and timing of exposure.

Laser Ablation–Inductively Coupled Plasma–Mass Spectrometry Imaging in Biology

“…291 The analysis of heavy metals in deciduous teeth is useful to reconstruct the lifetime lead exposure in children. 292,293 Arora and Austin et al 293,294 used the neonatal line as a reference line to analyze the deposition of elements (Mn, Pb) during fetal development. Savabieasfahani et al 295 found increased levels of Pb in deciduous teeth of children in war zones.…”

“…Evans et al first employed LA-ICP-MS in 1995 to measure the distribution of Zn, Sr, Cu, and Pb in teeth of walruses at different ages, and correlation of growth lines enabled the dating of past exposure events . The analysis of heavy metals in deciduous teeth is useful to reconstruct the lifetime lead exposure in children. , Arora and Austin et al. , used the neonatal line as a reference line to analyze the deposition of elements (Mn, Pb) during fetal development. Savabieasfahani et al found increased levels of Pb in deciduous teeth of children in war zones.…”

New Frontiers in Placenta Tissue Imaging

“…Quantification of the placental metabolic capacity, in addition to structure and vascular function, can lead to a better understanding of the interaction between placental function and fetal development. For example, Austin et al 28 elaborated on the importance of evaluating the spatial distribution of elemental metal species and their role in metabolic processes, such as oxygen transportation and mitochondrial function. Deficiencies in these essential metals and/or long-term exposure to exogenous heavy metals are associated with the negative health of a child.…”

Microspatial distribution of trace elements in feline dental hard tissues: early life exposure to essential and toxic elements

“…The known formation timing of the different dental tissue layers offers a record of exposure to environmental pollutants including heavy metals and other trace elements deposited during mineralization (4). Laser ablationinductively coupled plasma-mass spectrometry (LA-ICP-MS) is a well-established technique used to map elements in teeth, as well as other biological tissues, at a micrometer spatial resolution (28)(29)(30). Thus, the distribution of trace elements along histologic layers in teeth has been applied mainly to rodent, human, primate, and most recently equine teeth (16,(31)(32)(33)(34)(35).…”