At http://phys.org/print295252215.html …. some ten to forty tons of meteor dust enters our atmosphere every day – usually as a result of the Earth's orbit passing through the leftovers from a comet's passage. Comets, when approaching the Sun, out-gas a considerable amount of material, varying in degree from one comet to another. This leaves behind a trail that at first is dense and ribbon like, but over time disperses and becomes less of a problem. This post is prompted by the immanent arrival of the Perseids (on the 11th and 12th of August), a stream of material with an origin in Comet Tuttle Swift which approaches the Sun every 130 years. One if left wondering how much comet dust might have accumulated in the atmosphere when Earth encountered larger and denser streams of material. The estimate of 40 tons is based on current values – and the sky in the modern world is remarkably clear and free of space debris. What if Earth encountered one of the Taurid meteor streams – when they were newly formed. If they were as dense as Clube and Napier suggested, many tons of space dust would have collected in the upper atmosphere – leading to an opaque sky (and cooler temperatures).
At http://phys.org/print295257029.html … in this link we have a paper that tells us that meteor showers are 'celestial pollution' and again it is prompted by the Perseids. Shooting stars that burn up in the atmosphere let off gases – one of which is sodium.