> The embassies actively sprayed in offices, as well as inside and outside diplomatic residences — sometimes five times more frequently than usual. Many times, spraying operations were carried out every two weeks, according to embassy records.

This suggests that in fact it was the US government (following the host government's lead) that introduced the toxin into their environment. If so, it seems like the Cubans may be owed an apology.

But did the embassy use stronger concentration than Cuba? Or a different agent? Are any local Havanans experiencing these symptoms?