Gray area

Gray areas are the transitional spaces where containment procedures manage movement between a dangerous zone and the areas around it. In the investigations described in the book, they were made concrete through tarps, staging spaces, airlocks, chemical showers, and rules about which doors could open. These boundaries were essential to biocontainment, but they were not self-enforcing: needles, specimens, air, and people could carry contamination across them.

Definition and Function

At the Kitum Cave field site, the tarp nearest the cave marked a gray area between the cave’s Level 4 hot zone and the safer areas beyond. Investigators used it to take chemical showers and decontaminate their suits after entering the cave. A separate tarp covered the Level 3 staging area, where they changed into and out of protective suits, while another sheltered the Level 4 necropsy area. The arrangement turned an abstract safety principle into a sequence of marked spaces, each with a different purpose and level of risk.

The gray area was therefore not simply a place that was safe or unsafe. It was a controlled interface where workers and equipment passed from one condition to another, and where decontamination was meant to interrupt the movement of infectious material. Its significance depended on following the procedures built around it.

Fieldwork at Kitum Cave

During the Kitum Cave investigation, Gene Johnson’s team moved animals up Mount Elgon in stages to help them adjust to the climate. Near the cave, the team cleared underbrush and erected blue tarpaulins to organize the work. Inside the cave, investigators wore orange Racal suits designed for fieldwork involving airborne biohazards. They marked a route with avalanche poles and placed cages along it, including cages beneath bat colonies; outside the cave, the tarps separated changing, decontamination, and necropsy activities.

This layout connected the uncertain environment of the cave to a managed worksite. The cave was treated as a Level 4 hot zone, while the gray-area tarp provided a designated point for decontamination before workers moved back toward the staging area. The field arrangement carried the logic of high-containment laboratories into the jungle, but depended on physical separation and careful procedure rather than a permanent laboratory structure.

Airlocks and the Work of Crossing

Nancy Jaax’s entry into a Level 4 containment area shows how a threshold was managed step by step. Before reaching the hot side, she passed through security and a Level 3 staging area, where she and a colleague put on inner gloves and taped the cuffs. They carried supplies through an airlock; after entering the containment area, Jaax pulled the chemical-shower chain to begin a decontamination cycle intended to treat any agent that might have leaked into the airlock. The sequence made crossing itself part of the safety procedure.

At the Reston monkey house, Gene Johnson found a route through an empty adjoining office to plan an insertion point that would avoid unnecessary passage through the building. The team used a storeroom as its staging area and a closed corridor as a makeshift airlock. Once inside, Jerry Jaax and Captain Mark Haines encountered the corridor in darkness after realizing they had not brought flashlights. Even in an improvised setup, the airlock’s rule was exact: its inner and outer doors could not be open at the same time, because that could allow contaminated air to flow back into the staging room.

The boundary also sat close to ordinary public life. During the operation, the vehicles and insertion point were kept behind the monkey house, but a playground and day-care center lay beyond the underbrush on the hillside. The controlled route into the building thus existed beside spaces occupied by children, making the placement of the boundary and the discipline of crossing it consequential beyond the containment team.

When Boundaries Fail or Must Be Restored

Other episodes show why a marked transition alone could not guarantee safety. At Yambuku Mission Hospital, five hypodermic syringes were used to give injections to hundreds of outpatients and maternity patients; staff sometimes rinsed them, but often moved from one injection to the next without doing so. The account presents this practice as a possible route by which Ebola entered the schoolteacher who became the first known case in the Zaire outbreak. The hospital episode is not identified as a gray area, but it makes the stakes of an uncontrolled passage between people and their blood unmistakable.

A different breach of ordinary handling occurred when Peter Jahrling received samples from Monkey O53 wrapped in aluminum foil, with melting, red-tinged ice. He took them into a negative-pressure Level 3 laboratory, where such samples could be examined without a space suit. The packaging and leaking ice made the transfer into the laboratory an immediate concern, prompting him to explain safer sample-sending procedures to Dan Dalgard. The incident shows that containment depended not only on rooms and doors but also on how materials crossed into them.

The Reston operation ended by extending containment into a final cleanup. The decontamination team scrubbed the building with bleach, sealed exterior doors, windows, and vents with duct tape and plastic, and used thirty-nine electric frying pans to release formaldehyde gas inside the sealed structure. The gas remained for three days before the team returned to collect test samples. That effort represented the far end of boundary management: not merely controlling passage through a threshold, but treating the building and its contents so that the contaminated zone could be closed.