A critical review of perfluoroalkyl and polyfluoroalkyl substances (PFAS) landfill disposal in the United States.

Landfills manage materials containing per- and polyfluoroalkyl substances (PFAS) from municipal solid waste (MSW) and other waste streams. This manuscript summarizes state and federal initiatives and critically reviews peer-reviewed literature to define best practices for managing these wastes and identify data gaps to guide future research. The objective is to inform stakeholders about waste-derived PFAS disposed of in landfills, PFAS emissions, and the potential for related environmental impacts. Furthermore, this document highlights data gaps and uncertainties concerning the fate of PFAS during landfill disposal. Most studies on this topic measured PFAS in liquid landfill effluent (leachate); comparatively fewer have attempted to estimate PFAS loading in landfills or other effluent streams such as landfill gas (LFG). In all media, the reported total PFAS heavily depends on waste types and the number of PFAS included in the analytical method. Early studies which only measured a small number of PFAS, predominantly perfluoroalkyl acids (PFAAs), likely report a significant underestimation of total PFAS. Major findings include relationships between PFAS effluent and landfill conditions - biodegradable waste increases PFAS transformation and leaching. Based on the results of multiple studies, it is estimated that 84% of PFAS loading to MSW landfills (7.2 T total) remains in the waste mass, while 5% leaves via LFG and 11% via leachate on an annual basis. The environmental impact of landfill-derived PFAS has been well-documented. Additional research is needed on PFAS in landfilled construction and demolition debris, hazardous, and industrial waste in the US.

Temporal artery biopsy.

Giant cell arteritis is a common vasculitis in patients over the age of 50 years old. If not promptly recognized and aggressively treated with high-dose glucocorticoids, ischemia resulting in permanent vision loss or stroke can occur. Yet, the treatment with high-dose glucocorticoids over a long period of time can be problematic in this particular patient population given their age and associated comorbidities. Temporal artery biopsies (TAB) are an important diagnostic tool to evaluate patients with suspected giant cell arteritis. Herein, we explore indications for TAB and practical points in obtaining a TAB based on available evidence. We review the surgical procedure itself and associated complications. Lastly, we examine common pathological findings and considerations of alternative diagnoses.

Homocysteinemia due to MTHFR deficiency in a young adult presenting with bilateral lens subluxations.

The most common cause of isolated inherited homocysteinemia is a deficiency of the enzyme cystathionine ß-synthase (CBS). Clinical manifestations of CBS deficiency can include ectopia lentis, thromboembolism, marfanoid habits, and intellectual disability. CBS deficiency, which affects the transsulfuration pathway, is marked biochemically by elevated serum homocysteine and plasma methionine. We report a patient with homocysteinemia, low plasma methionine, and no significant neurological abnormalities who presented with bilateral subluxated crystalline lenses due to a 5,10-methylenetetrahydrofolate reductase (MTHFR) deficiency. MTHFR deficiency, a disorder in the remethylation pathway, can cause mild to severe disease, although most presentations include neurological involvement. MTHFR deficiency has not been previously associated with lens subluxation or complete dislocation. Prolonged exposure to elevated serum homocysteine levels is most likely the explanation for her ectopia lentis. This case expands the differential diagnosis of homocysteinemia and highlights the need for a correct diagnosis to optimize the clinical outcome of patients with this condition.