The study drew on 289 children enrolled in the PROGRESS cohort in Mexico, a long-running birth cohort designed to examine how environmental exposures shape child health. Rather than relying on blood or urine samples, which capture only recent exposure, the researchers turned to deciduous teeth, the baby teeth that children naturally shed. Teeth grow in layers much like tree rings, and the dentine that forms during specific developmental periods locks in a chemical record of what circulated in the child’s bloodstream at the time. By segmenting dentine along growth lines, the team was able to retrospectively quantify arsenic exposure for every week from sixteen weeks before birth through fourteen weeks after birth, an unprecedented temporal resolution for an immunotoxicology study.

When the children returned for a follow-up visit around age four to five, the investigators measured serum levels of immunoglobulin G antibodies directed against six vaccine antigens: measles, mumps, and rubella from the MMR vaccine, and diphtheria, tetanus, and pertussis from the DTP series. These antibodies are the immune system’s memory of vaccination, the molecular shield that prevents re-infection, and their concentrations in blood are a standard benchmark of how well a vaccine has taken hold. The measurements were performed using a multiplexed Luminex bead-based immunoassay, a technique that allows all six antibody targets to be quantified simultaneously from a small serum sample.

The statistical challenge was considerable. Because arsenic exposure was estimated for thirty consecutive weeks, the researchers needed a method that could detect when in that timeline exposure mattered, not just whether it mattered overall. They employed Distributed Lag Non-linear Models, or DLNMs, a framework originally developed in environmental epidemiology for studying delayed and time-varying effects of air pollution and temperature. The models related log2-transformed dentine arsenic concentrations to log2-transformed antibody levels across every week of the perinatal period, while adjusting for the child’s age, maternal education, parity, and child sex. The log2 transformation means the reported effects can be read as the change in antibody level associated with a doubling of arsenic exposure during a given week.

The results converged on a single, well-defined period. A doubling of arsenic exposure in the window spanning one week before birth to six weeks after birth was associated with significantly lower anti-measles antibody levels, with an estimated effect of minus 5.62 on the log2 scale and a 95 percent confidence interval running from minus 8.39 to minus 0.83. The same perinatal window showed a significant association for anti-rubella antibodies, with an effect estimate of minus 3.85 and a confidence interval from minus 6.99 to minus 0.63. In practical terms, children with higher arsenic exposure in the weeks surrounding delivery carried measurably weaker antibody defenses against measles and rubella years later, even though their vaccinations occurred long after the exposure itself.

Just as telling was what the analysis did not find. Arsenic exposure during the perinatal window showed no significant association with antibody levels against mumps, diphtheria, tetanus, or pertussis. Nor did earlier or later periods of prenatal and early postnatal exposure produce significant signals for any antigen. This selectivity is biologically intriguing. It suggests that the immune pathways supporting long-term antibody maintenance against measles and rubella may be more sensitive to arsenic’s interference than those supporting the other four antigens, or that different vaccine antigens rely on differently timed developmental programs of B-cell and plasma-cell maturation that vary in their vulnerability to toxic insult.

The timing of the susceptible window makes biological sense. The weeks surrounding birth are a period of profound immunological transition. The fetus must shift from the sterile, maternally protected environment of the womb to an microbe-rich world, and neonatal immune cells are actively learning to distinguish threat from tolerance. Maternal antibodies transferred across the placenta are waning while the infant’s own antibody production is just beginning. Arsenic is known to disrupt immune signaling, generate oxidative stress, and interfere with methylation processes that regulate gene expression, and a toxic exposure during this delicate choreography could plausibly leave a lasting imprint on how well vaccine memory is established and maintained.

The researchers also probed whether the effects differed between boys and girls, or between children who were breastfed at one month postpartum and those who were not, since both factors can shape immune development and arsenic dynamics. They found no heterogeneity by either sex or breastfeeding status, indicating that the association between perinatal arsenic and reduced measles and rubella antibodies appears to operate similarly across these subgroups. That consistency strengthens the case that the finding reflects a general biological vulnerability rather than an effect confined to a particular subset of children.

The methodological innovation deserves particular attention. Traditional exposure assessment in environmental health has long been hampered by the difficulty of reconstructing what a person was exposed to years or decades earlier. Baby teeth offer a solution that is both retrospective and precise, and their use here demonstrates how naturally shed biomaterials can transform the study of developmental toxicology. Combined with the DLNM framework, which treats exposure timing as a variable to be mapped rather than averaged, the approach allowed the team to draw a temporal map of vulnerability with weekly resolution, something conventional single-biomarker studies simply cannot achieve.

The public health implications are significant. Measles remains one of the most contagious human pathogens, and even modest reductions in population-level antibody levels can erode herd immunity and fuel outbreaks, a concern made vivid by recent resurgences of measles in countries where the disease was once controlled. Arsenic contamination of groundwater affects an estimated hundreds of millions of people worldwide, and in regions such as Mexico, where the PROGRESS cohort is based, exposure often begins before birth. If the findings are confirmed in other cohorts, they would add vaccine-preventable disease susceptibility to the long list of harms attributable to early-life arsenic exposure, and they would sharpen the argument for reducing arsenic exposure among pregnant women and newborns, whether through water filtration, dietary interventions, or regulatory limits on contaminated sources. The study, funded by the National Institutes of Health and led by researchers at the Icahn School of Medicine at Mount Sinai together with collaborators at Mexico’s National Institute of Public Health and other institutions, was published open access, with the authors reporting no competing interests.

Subject of Research: Perinatal arsenic exposure and vaccine-specific antibody levels in children

Article Title: Susceptible perinatal windows to arsenic exposure and serum antibody levels in children

Article References: Scotti, A., India-Aldana, S., Martinez, M., Arora, M., McRae, N., Lamadrid-Figueroa, H., Quataert, S. A., Estrada-Gutierrez, G., Torres-Olascoaga, L., Téllez-Rojo, M. M., Wright, R. O., Jusko, T. A., & Colicino, E. (2026). Susceptible perinatal windows to arsenic exposure and serum antibody levels in children. Environmental Health. https://doi.org/10.1186/s12940-026-01331-6

Image Credits: AI Generated

DOI: 10.1186/s12940-026-01331-6

Keywords: arsenic exposure, perinatal window, vaccine antibodies, measles, rubella, immunotoxicology, baby teeth, dentine, PROGRESS cohort, DLNM, humoral immunity, environmental health

Mammoth ivory is not simply an ancient analogue of elephant tusk used as a passive raw material. It is a biological composite with a highly ordered internal architecture. A tusk grows from the pulp cavity outward, depositing concentric layers of dentine marked by fine incremental lines, and is sheathed in an outer rind of cementum. In cross-section the material reveals radial features known as Schreger lines, the angle of which differs between the outer and inner zones of the tusk, while in longitudinal section the growth layers run in directions dictated by the natural curvature of the tusk. Any craftsperson who worked ivory repeatedly over a lifetime would have encountered these structures: the split that follows a growth layer, the fibrous pull of the dentine, the hard, dense cementum shell that behaves differently from the interior. The new analysis suggests that the Mizyn carvers did not treat such features as obstacles but as affordances, working with the grain of the material so that the natural zoning of the tusk became part of the design itself.

The Mizyn assemblage, excavated from a well-preserved Upper Palaeolithic dwelling complex, includes several small figurines carved from mammoth ivory, most famously a group of female statuettes interpreted by many archaeologists as representations of the female form, together with decorated objects that carry dense networks of meandering lines, chevrons and bands. These ornaments have long been discussed in the archaeological literature as some of the earliest examples of complex geometric design in Europe, and competing explanations have been offered for their meaning, from calendrical notations and symbolic counting systems to purely aesthetic or social functions. The new study reframes the question by directing attention away from iconography alone and toward the interaction between carver and material, asking what the ivory itself contributed to the finished forms.

The central claim of the research is that specific anatomical zones of the tusk map onto specific elements of the figurines. The outer cementum layer, which is thin, hard and texturally distinct, is proposed to correspond to the banded and ribbed elements of the decoration, so that the carver deliberately exposed or accentuated the natural surface zone rather than removing it. The underlying dentine, with its layered and fibrous character, is linked to the smoothly modelled volumes of the figurine bodies, where the material could be shaped along its growth lines with less risk of splitting. Where the pulp cavity once lay, the carving in some cases produced hollows or depressions that were then incorporated into the design. In this reading, the sinuous ornament that covers the Mizyn figurines echoes the very layering of the tusk from which they were made, a formal echo produced by following the internal architecture rather than fighting it.

From a technical standpoint, the argument rests on the correspondence between the directional properties of ivory and the orientation of the carved features. Ivory splits predictably along and between growth layers, and it behaves differently in tangential and radial planes, so a carver who wished to avoid fracture would align cutting directions with the natural structure of the material. The study’s authors point out that the recurring placement of parallel line groups and banded ornament on the figurines is consistent with the exposure of natural layering planes, and that the overall silhouettes of several pieces can be understood as the result of detaching suitable blanks from particular zones of the tusk. The curvature of a mammoth tusk, which is strongest near the pulp cavity and gentler toward the outer wall, imposes its own geometry on any elongated object cut from it, and the figurines appear to reflect that imposed geometry in their profiles and proportions.

This material-driven interpretation has significant implications for how archaeologists read Upper Palaeolithic art more broadly. If the ornament and form of the Mizyn figurines arose in part from the structure of the raw material, then the designs should not be decoded as if they were arbitrary symbols written onto a neutral surface. Instead, they represent a dialogue between maker and material, in which the carver’s knowledge of tusk anatomy, accumulated through generations of working ivory for tools, ornaments and architecture, shaped what was visually possible and meaningful. The famous meander patterns of Mizyn, sometimes compared to painted decoration on later ceramics, may in this light be understood as design conventions that emerged from the layered appearance of ivory itself, then standardised and repeated across multiple objects because the structure of the material invited that particular visual language.

The claim also speaks to a long-standing debate about the origins of representation. Traditional accounts of Palaeolithic figurines emphasise either naturalistic imitation of the human body or symbolic abstraction, treating the choice of material as secondary. The Mizyn study belongs to a growing body of work that places the material at the centre of the creative process, a perspective sometimes described as material engagement. On this view, the properties of ivory did not merely constrain the carvers; they actively suggested forms. The natural zones of the tusk offered a ready-made differentiation of surface and interior, hard and soft, outer and inner, which the figurines appear to exploit in rendering contrast between the decorated exterior of a body and its smooth volumes. The result, the authors argue, is an art style co-authored by the biology of the mammoth and the skill of the human hand.

The research also carries implications for the study of mammoth ivory exploitation in the East European Plain, where sites such as Mizyn are famous above all for their monumental architecture built from deliberately arranged mammoth bones and skulls. Understanding how the internal structure of ivory guided the design of small carvings adds a fine-grained dimension to what is already known about how intensively these communities engaged with mammoth remains. The same anatomical knowledge that allowed a carver to predict how a tusk would split for a projectile point or an ornament blank also governed the production of figurines, suggesting a unified technological system in which subsistence technology and symbolic production shared a single body of craft expertise. In that sense, the figurines are documents not only of Ice Age belief or aesthetics but of a sophisticated practical understanding of a difficult and highly valued raw material.

For the wider public, the study offers a striking image: an Ice Age artist in Ukraine holding a fragment of mammoth tusk, reading its layered interior the way a carpenter reads the grain of wood, and finding within that ancient biological structure the lines, bands and forms that would become one of the signature styles of the European Upper Palaeolithic. If the authors are correct, the celebrated figurines of Mizyn are, in a very literal sense, portraits of the material from which they were made, and the mammoth that grew the tusk deserves to be counted among the anonymous collaborators who shaped the earliest art of the region.

Subject of Research: The influence of mammoth ivory's internal structure on the design of Upper Palaeolithic figurines at Mizyn, Ukraine.

Article Title: Internal structure of Mammoth ivory inspired the design of Mizyn (Ukraine) Upper Palaeolithic figurines

Article References: Radchenko, S., Naumenko, O., Kiosak, D., Mansrud, A., Needham, A., & Little, A. (2026). Internal structure of Mammoth ivory inspired the design of Mizyn (Ukraine) Upper Palaeolithic figurines. npj Heritage Science. https://doi.org/10.1038/s40494-026-02988-5

Image Credits: AI Generated

DOI: 10.1038/s40494-026-02988-5

Keywords: Mizyn, Mezin, mammoth ivory, Upper Palaeolithic, figurines, portable art, Ukraine, tusk structure, cementum, dentine, Ice Age art, material engagement