Telma Ortegal

Parque Estadual Telma Ortegal (PETO) is a small state park in the municipality of Abadia de Goiás, about 24 kilometers southwest of Goiânia in central Brazil. ^[1] Covering roughly 165.96 hectares, it was created in 1995 and stands out for a singular reason: it houses the permanent repository of radioactive waste from the 1987 Goiânia Cesium-137 accident, one of the worst radiological disasters ever to occur outside a nuclear facility. ^[2] Within its boundaries operates the Centro Regional de Ciências Nucleares do Centro-Oeste (CRCN-CO), which monitors the Cesium-137 deposit. Beyond this defining function, the park protects a representative fragment of Cerrado threatened by the urban expansion of the Goiânia metropolitan region. Managed by SEMAD under a special regulatory framework, Telma Ortegal combines nuclear-waste stewardship, environmental monitoring, and the conservation of urban savanna.

Despite its small size and proximity to urban Goiânia, the park sustains a notable diversity of Cerrado fauna. Mammals recorded or reported in the area include crab-eating foxes, six-banded armadillos, southern tamanduas, tufted capuchins, and black-tufted marmosets, with occasional records of pampas deer and maned wolves dispersing from larger fragments. Birdlife is varied, featuring red-legged seriemas, toco toucans, aracaris, burrowing owls, and many Cerrado songbirds such as tanagers and flycatchers. Reptiles include tegus, boa constrictors, and several lizard species, while amphibians breed in seasonal pools and stream margins during the wet season. Because it is one of the few protected Cerrado remnants in the metropolitan area, the park plays an outsized role in maintaining local wildlife populations and genetic connectivity between the region increasingly isolated natural fragments.

The park vegetation is dominated by cerrado sensu stricto and cerradão on well-drained soils, with gallery forest along seasonal streams and small wet-prairie patches (veredas) at springs. Characteristic Cerrado trees include pequi, lobeira, sucupira-preta, jatobá-do-cerrado, ipê-amarelo, and barbatimão, while gallery forests host embaúba, copaíba, and wild figs. The herbaceous layer contains native grasses, Vellozia on shallow soils, and fire-adapted forbs that resprout after seasonal burns, and buriti palms mark the moist veredas. Given the park very small area, maintaining the quality of its interior habitats and minimizing edge effects from surrounding urban and agricultural land is critical to conserving this flora. The vegetation also provides an important buffer and green setting around the sensitive nuclear-monitoring facility, reinforcing the park dual conservation and containment roles.

The park sits on the Central Brazilian Plateau within the Brasília Fold Belt, underlain by Precambrian metamorphic rocks — schists, phyllites, and quartzites associated with the Araxá Group. Prolonged tropical weathering has produced deep red-yellow latosols and cambisols that are acidic and aluminum-rich, conditions typical of Cerrado environments. The terrain is gently undulating at elevations around 800 to 900 meters, dissected by small streams that drain toward tributaries of the Rio Meia Ponte. Scattered outcrops of quartzite and lateritic concretions (canga) punctuate the landscape, while sandy alluvial and hydromorphic soils along the streams support gallery forests and veredas. The stable, deeply weathered substrate underpins both the Cerrado vegetation and the site suitability for the secure, long-term containment and monitoring of the Cesium-137 waste deposit housed within the park.

Telma Ortegal has a tropical savanna climate (Köppen Aw) with two sharply defined seasons. The summer months from October through April are warm and humid and deliver the great majority of the annual rainfall of about 1,500 millimeters, largely in intense afternoon thunderstorms. Winters from May through September are dry, sunny, and cooler, with relative humidity often dropping below 30 percent and winds that raise fire risk. Temperatures average around 24 to 28 degrees Celsius through the year, though clear winter nights can dip below 12 degrees. This strongly seasonal regime governs the rhythms of the Cerrado vegetation — leaf fall, flowering, and fire-adapted regrowth — and also shapes management routines around fire prevention during the dry months, an especially important concern given the park small size and its sensitive monitoring facilities.

The area around Abadia de Goiás was historically occupied by Indigenous groups before its incorporation into colonial Brazil, and rural settlement intensified after the founding of Goiânia as the state capital in 1933. The defining modern event for the region, however, was the 1987 Goiânia radiological accident: a discarded radiotherapy source containing Cesium-137 chloride was scavenged and breached in the city, contaminating 271 people and causing four confirmed deaths. ^[1] The resulting radioactive waste was consolidated and stored at a purpose-built repository near Abadia de Goiás, which became separate from Goiânia as a municipality in the 1990s. The creation of the park around this deposit, and its naming for Telma Ortegal — the first mayor of Abadia de Goiás — ties the site human history directly to one of Brazil most significant environmental and public-health episodes.

Parque Estadual Telma Ortegal was created by Goiás State Law No. 12.789 on 26 December 1995, established as a condition of the environmental licensing for the radioactive-waste deposit produced by the 1987 Cesium-137 accident. ^[1] It was named in honor of Telma Ortegal by State Law No. 13.166 of 17 November 1997. The park operates under a special regulatory framework linked to its nuclear-monitoring role and is managed by SEMAD, with the CRCN-CO facility overseeing the Cesium-137 repository within its boundaries. Over time, the park mission has broadened from waste containment to include Cerrado conservation and environmental education, developed through partnerships with schools, universities, and NGOs. Its history is therefore inseparable from the aftermath of the Goiânia accident, which remains the reason for its existence and shapes its unusual dual identity as both a monitoring site and a nature reserve.

The park offers short interpretive trails through Cerrado and gallery forest that are popular with school groups and residents seeking nature walks close to Goiânia. Highlights include a small waterfall along an internal stream, seasonal wildflowers, active termite mounds, and bird-rich forest edges where marmosets, toucans, and colorful songbirds can be observed. Iconic Cerrado plants such as pequi trees and flowering ipês are focal points of interpretation. Given the park dual role as a nuclear-monitoring site and a small reserve, visitation is managed carefully: access is generally by scheduled group programs or individual visits coordinated with SEMAD, and educational workshops are periodically organized with local environmental groups. The combination of accessible Cerrado experiences and the site distinctive history gives the park an unusual educational appeal for the metropolitan public.

The park is located in Abadia de Goiás, about 24 kilometers from downtown Goiânia and reached via the BR-060/GO-060 corridor. ^[1] Because of its small size and specialized management, visitation is typically arranged as scheduled group programs or individual visits coordinated in advance with SEMAD, rather than open walk-in tourism. Goiânia, close by, provides the nearest full range of accommodation, restaurants, and transport services, making the park an easy half-day outing for visitors based in the city. Guests should bring water, sun protection, and insect repellent, and follow staff instructions regarding trail access and conduct, particularly given the presence of the nuclear-monitoring facility. For nature enthusiasts staying in Goiânia, the park provides a convenient opportunity to experience Cerrado without long-distance travel.

As a small protected area embedded in a rapidly urbanizing setting, Telma Ortegal faces conservation challenges including edge effects, invasive species, illegal dumping, and pressure from adjacent development. Management prioritizes maintaining habitat quality, controlling invasive African grasses, and preventing wildfires that could devastate such a limited area. Uniquely, the park integrates conservation with nuclear stewardship: the CRCN-CO station operates within its boundaries under federal-state oversight to ensure continuous monitoring of the Cesium-137 waste deposit, making environmental safety and radiological surveillance intertwined objectives. Environmental education is a cornerstone of the park strategy, with outreach to schools, universities, and community groups that also helps build public understanding of the legacy of the 1987 accident. By conserving Cerrado and sustaining ecosystem services beside a major city, the park contributes to regional connectivity while safeguarding a sensitive site.