Examples of poison emission

In a Central American town, a corpse leaks a black liquid from its eyes...

...and from its torso.

The streets of the town are littered with victims.
(Maya y Alejandro)

Hana uploaded a video...

...of numerous bodies dead from the affliction.
(Hana's website)

When separated from Alejandro...

...Maya's tears turn black...

...and she is responsible for the death of many people...

...including a coyote called Hulk.
(Four Months Later...)

Maya's ability affects Nidia their border guide, but she is revived by Alejandro.
(Lizards).

Maya entices the police to anger her...

...which affects everyone in the building...

...and shows her brother her tears.
(Kindred)

When Sylar tells Maya that Derek is ratting her out, her tears flow...

...and Sylar begins to fall victim to them.
(The Kindness of Strangers)

Sylar persuades Maya to use her ability to kill the Citizen's Border Patrol...

...which she does.
(The Line)

Maya's first black tear...

...turns to many...

...killing Gloria...

...Gilberto...

...and everyone at the Alejandro's wedding reception.
(Four Months Ago...)

Maya's ability manifests again at a convent...

...overwhelming a Venezuelan sheriff...

...until Alejandro causes the tears to disappear.
(Four Months Ago...)

After Sylar provokes Maya to use her ability...

...Sylar falls to the ground...

...and Maya manages to reverse her power without Alejandro's help.
(Truth & Consequences)

After finding out the truth about Sylar, Maya's ability erupts...

...affecting Sylar...

...Molly...

...and Mohinder.
(Powerless)

Maya gets upset...

...affecting Mohinder.
(The Second Coming)

In fear, Maya's power activates...

...poisoning Mohinder.
(Angels and Monsters)

After taking Maya's ability, Arthur demonstrates it himself.
(Eris Quod Sum)