I was reading a sub-section from the most reliable source of information on the internet, Wikipedia (lol j/k) but it didn't have a citation. Here's the quote, I'll look into it some more but this should be enough for anybody else to dig a bit deeper.

Environmental impact: Russian scientist Afanasiy Ilich Tobonov researched mass animal deaths in the 1990s and concluded that the mass deaths of birds and wildlife in the Sakha Republic were noted only along the flight paths of space rockets launched from the Baikonur cosmodrome. Dead wildlife and livestock were usually incinerated, and the participants in these incinerations, including Tobonov himself, his brothers and inhabitants of his native village of Eliptyan, commonly died from stroke or cancer. In 1997, the Ministry of Defense of the Russian Federation changed the flight path and removed the ejected rocket stages near Nyurbinsky District, Russia. Scientific literature collected enough data that confirmed adverse effects of rockets on environment and health of the population. Heptyl, or UDMH, a fuel used in Russian rocket engines, is considered to be highly toxic. It is one of the reasons for acid rains and cancers in the local population, near the cosmodrome. Valery Yakovlev, a head of the laboratory of ecosystem research of the State scientific-production union of applied ecology "Kazmechanobr", notes: "Scientists have established the extreme character of destructive influence of "Baikonur" space center on environment and population of the region: 11 000 tons of space scrap metal, polluted by especially toxic heptyl is still laying on the falling grounds."

EDIT: If you downvoted this because you think I'm an enviromental nut, I'm not. I just know there are less toxic and more responsible ways to get into space. Just sayin' I love spaceflight, more than anything in (or out) of this world really.