The study, conducted by researchers at the University of Mississippi School of Pharmacy in partnership with the Mississippi Division of Medicaid and published in Advances in Therapy, analyzed deidentified administrative claims from January 2023 through December 2025. The team identified 8,495 GLP-1 receptor agonist users overall and narrowed the cohort to 3,968 adults who initiated therapy between July 2023 and June 2025, each with six months of continuous enrollment before and after starting the medication. The population was strikingly homogeneous: 92.52 percent were female, 50.28 percent were Black, and nearly 62 percent were younger adults aged 18 to 39. Hypertension and depression were the most common coexisting conditions, and most members were enrolled in managed care organizations rather than fee-for-service plans.

The headline numbers tell a story of steady erosion. Mean adherence, measured by the proportion of days covered, a standard metric that divides the total days a patient has medication on hand by the total days in the observation window, stood at 0.76 at three months but fell to 0.65 by six months. The proportion of members meeting the conventional adherence threshold of at least 80 percent of days covered dropped from 56.85 percent at three months to 38.16 percent at six months. Persistence, defined as continuous therapy without a gap of 60 days or more, followed the same downward slope, falling from 72.98 percent to 51.03 percent over the same interval. In the subgroup followed for a full year, mean adherence sank to 0.54, with only 25.26 percent adherent and 36.67 percent persistent.

What makes this study particularly valuable is its timing. Most prior real-world analyses of GLP-1 adherence were conducted during the nationwide drug shortage that ran from 2022 through February 2025, a period when supply constraints made it nearly impossible to distinguish voluntary discontinuation from involuntary interruption. Because this analysis extends through December 2025, it captures one of the first pictures of adherence under conditions of stable drug availability. The researchers found that adherence improved progressively across initiation cohorts: members who started therapy in the first half of 2025 consistently outperformed those who began in 2024, who in turn fared better than the 2023 pioneers. Among 2023 initiators, only 47.77 percent were adherent at three months, compared with 61.01 percent of 2025 initiators.

To move beyond aggregate statistics, which can mask enormous individual variation, the team employed group-based trajectory modeling, a statistical technique that clusters individuals who follow similar longitudinal patterns of behavior. The model input was the continuous proportion of days covered calculated for each 30-day interval, and the optimal five-group quadratic solution was selected using the Bayesian Information Criterion, the logged Bayes factor, a minimum group membership threshold of five percent, and clinical interpretability. The result was a taxonomy of medication-taking behavior that is far more nuanced than a single adherence rate could ever convey.

The largest group, comprising 52.27 percent of members, was labeled consistent adherent, maintaining high medication coverage throughout follow-up. The remaining members scattered across four suboptimal pathways. The delayed decliner group, 13.53 percent of the cohort, held steady for roughly three months before sliding. The consistent decliner group, 12.85 percent, showed a steady reduction from the outset. The fluctuating adherent group, 11.14 percent, cycled through declines and partial recoveries, a pattern that may reflect intermittent access barriers or wavering motivation. Most concerning was the rapid discontinuer group, 10.21 percent, who abandoned therapy by the second month and never returned, a trajectory often associated with early adverse effects such as nausea and gastrointestinal distress, or with immediate obstacles to refilling prescriptions.

Multinomial logistic regression, using the consistent adherent group as the reference, illuminated who was most at risk of falling off course. Members who initiated therapy in July through December 2023 had more than twice the odds of becoming rapid discontinuers compared with 2025 initiators, an odds ratio of 2.10, likely reflecting the chaos of the shortage era. Age mattered profoundly: members aged 40 to 64 had significantly lower odds of suboptimal trajectory membership than those aged 18 to 39, perhaps because younger patients perceive less disease severity, have shallower roots in the healthcare system, and face fewer obesity-related complications that motivate sustained treatment. Black members had higher odds of belonging to the rapid discontinuer and fluctuating adherent groups than white members, a disparity the authors attribute to structural and socioeconomic barriers rather than race itself. Enrollment in a managed care organization was protective, cutting the odds of rapid discontinuation by roughly a third, presumably because care coordination, medication management programs, and proactive outreach help keep patients engaged in ways that fragmented fee-for-service coverage cannot.

Clinical characteristics painted a more complicated picture. Type 2 diabetes and cardiovascular comorbidities were associated with higher odds of suboptimal trajectories, possibly reflecting greater clinical complexity and competing therapeutic priorities that crowd out obesity treatment. Hypertension, paradoxically, was protective, reducing the odds of delayed decliner membership. Sex showed no significant association, a departure from prior studies, though the authors note their cohort was so overwhelmingly female, reaching 93 percent of initiators in early 2025, that detecting sex differences may have been statistically impractical. Sleep apnea, fatty liver disease, hyperlipidemia, kidney conditions, and depression were not significantly linked to trajectory membership.

The policy implications are considerable. As of January 2026, only 13 state Medicaid programs covered at least one GLP-1 receptor agonist approved for weight management, and several have since withdrawn or restricted coverage. Coverage alone, the Mississippi experience suggests, is insufficient to guarantee therapeutic engagement. Fewer than five percent of initiators in the program received counseling services before starting therapy, a strikingly low uptake given that discontinuation is consistently associated with rapid weight regain and loss of cardiometabolic benefit. The authors argue for expanded care management, patient education, behavioral counseling, and side effect support, alongside robust lifestyle programs that can mitigate regain among those who stop the drugs. The temporal improvement across cohorts also offers a hopeful signal: fixing structural access barriers, as the shortage resolution did, produces measurable gains in continuity. For the other states weighing coverage decisions, Mississippi’s data provide a rare, unvarnished look at what happens when expensive, effective medications meet a high-need population, and a reminder that the hardest part of obesity pharmacotherapy may begin not at the first injection, but at the second and every one after.

Subject of Research: Real-world adherence and persistence to GLP-1 receptor agonist anti-obesity medications among Medicaid enrollees

Article Title: Real-World Adherence Patterns and Predictors of GLP-1 Receptor Agonist Use for Obesity Management in a Medicaid Population

Article References: Bazzazzadehgan, S., Pittman, E., Lin, L.-Y., Qi, J., Ly-Ha, A., Smith, D., Kirby, T., Vest, T. A., Bentley, J. P., & Bhattacharya, K. (2026). Real-World Adherence Patterns and Predictors of GLP-1 Receptor Agonist Use for Obesity Management in a Medicaid Population. Advances in Therapy. https://doi.org/10.1007/s12325-026-03806-x

Image Credits: AI Generated

DOI: 10.1007/s12325-026-03806-x

Keywords: GLP-1 receptor agonists, anti-obesity medications, Medicaid, medication adherence, persistence, group-based trajectory modeling, obesity, health disparities, Mississippi, drug shortage, proportion of days covered, health policy

The Mississippi River Basin covers approximately 41% of the contiguous United States and encompasses roughly 65% of U.S. croplands. For generations, farmers in this area have utilized liming to manage soil pH, reduce acidity, and improve crop yields. The practice involves spreading crushed limestone over agricultural fields. While the primary goal has historically been agricultural productivity, the new study reveals that this activity also has significant implications for climate change mitigation by removing carbon dioxide from the atmosphere.

Tim Jesper Suhrhoff, a geochemist at Yale and the first author of the study, noted that the results align climate action with practices that are already beneficial for farmers. Suhrhoff, a postdoctoral associate at the Yale Center for Natural Carbon Capture, explained that the study provides a more complete picture of the liming process. The research team analyzed more than 120 years of historical records to trace the long-term effects of adding crushed carbonate rock to agricultural soil. This extensive dataset allowed the researchers to evaluate the net carbon impact of liming over a significant period.

The mechanism by which liming stores carbon is similar to a related practice known as enhanced weathering. In this process, adding crushed rock to soil reacts with carbon dioxide to form stable bicarbonate ions. These ions can be transported through soils, groundwater, and rivers, eventually reaching the ocean where the associated carbon can remain stored for long periods. While enhanced weathering has often focused on silicate rocks, the new study demonstrates that carbonate-based liming also contributes to net carbon removal when evaluated against a realistic baseline.

A key advance of the study is its accounting for what would have occurred without liming. The researchers noted that even in the absence of lime, acidity generated by fertilizer use and air pollution would cause chemical reactions in the soil and water that release carbon dioxide. By comparing the liming scenario to this more complex baseline, the study finds that liming results in long-term net carbon removal. This approach provides a more accurate assessment of the practice’s climate benefits than previous methods that did not account for these background emissions.

The findings challenge the way agricultural liming is currently treated in conventional greenhouse gas accounting. The default methodology of the Intergovernmental Panel on Climate Change treats the carbon contained in applied lime as emitted carbon dioxide. However, the study suggests that a more complete framework could recognize situations where liming benefits both farmers and the climate. Suhrhoff and his colleagues emphasized that they support the IPCC’s efforts to document emissions but argued that accounting for liming’s net carbon removal would better align climate and agricultural incentives.

Christopher Reinhard, a professor at the Georgia Institute of Technology and co-corresponding author of the study, stated that better soil pH management can improve yields and soil health while also benefiting the climate. He suggested that this provides another reason to expand access to liming where it is sensible. The study’s results indicate that carbonate-based enhanced weathering may deserve renewed attention as a strategy for scaling up climate change mitigation. The researchers highlighted the potential for this practice to contribute significantly to global carbon removal efforts if adopted more broadly.

Noah Planavsky, a professor of Earth and planetary science at Yale and a corresponding author, described the study as a unique opportunity to trace historical records that demonstrate the effectiveness of enhanced weathering. He noted that the process already provides benefits to farmers and is now shown to be beneficial for the climate by removing carbon dioxide from the atmosphere. Planavsky, who is also a faculty member of the Yale Center for Natural Carbon Capture, emphasized the importance of understanding the long-term impacts of agricultural practices on the global carbon cycle.

The study estimates that since 1900, liming in the Mississippi River Basin has removed between 300 and 400 million metric tons of carbon dioxide. This substantial amount of carbon removal suggests an opportunity to scale up enhanced weathering by helping more farmers conduct agricultural liming. However, the researchers noted that the climate impact of liming will vary depending on local factors such as existing soil acidity, soil buffering capacity, and hydrology. The magnitude and duration of any upfront carbon dioxide emissions, as well as the efficiency of carbon removal, depend on these specific conditions.

Despite the promising findings, the researchers cautioned that the results from the Mississippi River Basin will not always transfer directly to every agricultural setting. Planavhoff noted that many farmers currently cannot afford optimal soil pH management and suggested that funding mechanisms could be developed to support this process by taking into account the carbon removals. The study was supported by funding from the Yale Center for Natural Carbon Capture, the Swiss National Science Foundation, the Environmental Defense Fund, the Foundation for Science and Technology, and the U.S. Department of Energy. Co-authors of the study include researchers from Yale, the Georgia Institute of Technology, Newcastle University, and Texas A&M University.

Subject of Research: Climate Change

Article Title: Adding limestone to Mississippi River Basin farmlands acts as a major carbon sink, study finds

Article References: Adding limestone to Mississippi River Basin farmlands acts as a major carbon sink, study finds. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: carbon sink, agricultural liming, Mississippi River Basin, enhanced weathering, soil management, climate mitigation, Yale University, Nature journal, Adding, limestone, Mississippi, River

The study, published in the journal Environmental Geochemistry and Health, is described by its authors as the first city-wide assessment in the United States to systematically measure contamination by potentially toxic elements in soils at community-reported illegal dumping sites. Led by Erica D. Walker of Brown University’s School of Public Health, the team measured eight elements: the metalloid arsenic along with cadmium, chromium, copper, manganese, nickel, lead and zinc. Jackson made an urgent and instructive setting. The city has struggled for years to maintain reliable waste collection, and a 2023 breakdown in negotiations halted residential trash pickup across the city, during which illegal dumping rose sharply.

The methodological heart of the study is portable X-ray fluorescence, or pXRF, an instrument technique that bombards soil samples with X-rays and reads the characteristic fluorescent signatures of the elements they contain. At each of the 45 sites, the researchers collected soil from 20 locations, at two depths, and combined the samples into composite surface and subsurface specimens. The soils were dried, sieved to below 250 micrometers, and analyzed in triplicate. On a subset of 13 sites, the team also ran laboratory analysis by inductively coupled plasma optical emission spectrometry, or ICP-OES, following standard acid digestion, to provide an independent comparison.

The results revealed a clear hierarchy of contamination. Lead, copper and zinc dominated the enrichment, co-occurring across sites and reaching striking extremes: lead peaked at 2,910 milligrams per kilogram at depth, zinc at 1,630, and copper at 1,220. The distributions were strongly right-skewed, so a handful of extreme sites drove the averages. Surface lead, for example, averaged 226 milligrams per kilogram against a median of just 84.7. Cadmium, by contrast, was barely detectable by the field instrument, and the few pXRF readings that did appear proved to be spectral artifacts, contradicted by laboratory values 30 to 570 times lower.

Perhaps the most elegant result is the separation of two distinct geochemical fingerprints using field-portable screening alone. Principal component analysis and hierarchical clustering, applied to the depth-specific measurements, independently grouped chromium, nickel and iron together, while placing lead, zinc, arsenic and copper in a separate cluster. The iron association points to a lithogenic origin, elements present because of the local geology, since Jackson’s soils sit on deep silt deposits of Peoria Loess. The lead-zinc-arsenic-copper group, by contrast, is consistent with waste inputs from tires, wiring, plumbing, electronics, painted debris and treated wood. Partial-extraction recoveries from the laboratory subset corroborated the split: chromium was recovered at roughly a tenth of its total concentration by nitric acid extraction, as expected for chromium locked in silicate phases, while lead and copper were recovered at about half, consistent with more readily extractable, waste-derived forms.

The depth data carry the study’s central practical warning. For every element measured, surface and 15-centimeter concentrations were significantly correlated, and for lead the correlation was nearly perfect, at r = 0.982. In the cluster analysis, every element paired with its own counterpart at the other depth before joining any other element, a structural signature of vertical coherence. The researchers are careful to note that they sampled sites as found, with waste present, so the depth data describe contamination already in the ground beneath active dumping sites. But the inference for cleanup policy is the same: clearing surface waste, or even removing the uppermost soil layer, would not eliminate the elemental burden at these locations.

To translate concentrations into health-relevant terms, the team ran a screening-level risk assessment following United States Environmental Protection Agency guidance, evaluating incidental soil ingestion, dermal contact and inhalation of resuspended particles for a hypothetical child and adult resident. For a child, the hazard index exceeded unity at 21 of the 45 sites, with a maximum of 2.98. For adults, it stayed below unity everywhere. But the drivers of that calculated hazard are largely natural: arsenic and manganese, both geogenic in this setting, dominated the index, and the EPA’s arsenic screening level of 0.68 milligrams per kilogram actually sits below the local background of 6.9. Remove arsenic from the calculation, and only one site remains above unity. The honest reading, the authors argue, is that the elements driving computed hazard are mostly natural, while the element driving regulatory exceedance is the one attributable to dumping.

That element is lead. Because the EPA assigns lead no reference dose, evaluating it instead through blood-lead modeling, the researchers compared depth-averaged lead concentrations against absolute regulatory thresholds. Lead exceeded the residential soil screening level of 200 milligrams per kilogram at 11 of the 45 sites, roughly a quarter, and exceeded the 600 milligram per kilogram removal management level at four sites. Exceedances appeared in five of the six wards containing sites, most often in Ward 5. Since lead is also the element that the component, cluster and extraction evidence identifies most clearly as waste-derived, the authors describe this combination of regulatory exceedance and unambiguous anthropogenic attribution as the study’s principal public health finding.

The study is equally candid about its own limits, and those limits carry lessons for how such screening should be used. The contamination factor and degree of contamination indices the team calculated are useful for ranking and prioritizing sites, but they depend entirely on the chosen background values, and the researchers show that classifications derived from total pXRF measurements and from partial-extraction laboratory measurements agreed for only one of 13 paired sites. Chromium hazard remains unresolved, because the field instrument measures total chromium and cannot distinguish the relatively benign Cr(III) form from the toxic Cr(VI); under a worst-case assumption the child hazard quotient for chromium would jump from 0.001 to 1.42. No conclusions about mobility or bioavailability were drawn, since leaching tests and organic carbon measurements were not performed.

What emerges is a practical blueprint for resource-limited cities. Portable XRF screening, embedded in a public repository where residents and field teams document dumping locations, waste composition and exposure observations, makes city-wide assessment affordable and repeatable, while costlier laboratory analysis is reserved for high-priority sites. The spatial pattern in Jackson argues for site-by-site triage rather than uniform cleanup standards, because contamination is decentralized and scattered across individual locations that differ in size and contents. The authors’ closing message is blunt: a former dumping site converted into a community garden or playground may look fully restored while still carrying lead, arsenic and other elements that a visible cleanup did nothing to remove. A site is not recovered when it merely looks clean; it is recovered when a city can show that the land is safer for the people who live, work, garden or play on it.

Subject of Research: Soil contamination by potentially toxic elements at illegal dumping sites in Jackson, Mississippi

Article Title: Hidden toxicities: assessing city-wide contamination by potentially toxic elements from illegal dumping in Jackson, Mississippi

Article References: Walker, E. D., Klevan, C., Mathews, K., Mandalapu, S. V., Nica, C., & Ibrahim, N. (2026). Hidden toxicities: assessing city-wide contamination by potentially toxic elements from illegal dumping in Jackson, Mississippi. Environmental Geochemistry and Health, 48(15), Article 603. https://doi.org/10.1007/s10653-026-03450-y

Image Credits: AI Generated

DOI: 10.1007/s10653-026-03450-y

Keywords: illegal dumping, soil contamination, potentially toxic elements, lead, portable X-ray fluorescence, Jackson Mississippi, environmental geochemistry, public health, risk assessment, urban soil, ICP-OES, environmental justice