Evidence for Fossil Fuel PM₁ Accumulation in Marine Biota

When fine particulates such as those with a diameter of approximately 1 μm (particulate matter, PM₁) are released from fossil fuel combustion into the air, they warm the atmosphere and contribute to millions of premature deaths in humans each year. Considerable quantities of PM₁ eventually enter the oceans as suspended particulates, yet subsequent removal mechanisms are poorly understood. In fact, the presence of PM₁ in marine biota has never been reported. Since sea anemones are opportunistic suspension feeders, they are anticipated to incorporate and accumulate PM₁ in their bodies. By histological examination, PM₁ was detected in 21 of the 22 sea anemones collected from Taiwan and Southeast China, with a depth of intertidal zone to 1000 m. PM₁, if present, was always detected in endodermal layers and had the same dominant color (i.e., black, brown, or green) in different species from the same site. The bioaccumulation factor of PM₁ in sea anemones was approximately 5–7 orders of magnitude. Based on radioisotope ¹⁴C results, the contribution of fossil fuel source PM₁ was 8–24%. Regardless of PM₁’s color, S and Fe were commonly detected by scanning electron microscopy and energy-dispersive spectrometry (SEM-EDS), suggesting anthropogenic sources. Furthermore, a maternal transfer of materials was suggested based on the existence of PM₁ in sea anemone eggs and in brooding and released juveniles. The significance of PM₁ accumulation by biota in aquatic ecosystems and the potential risk to living organisms via food webs warrant further investigation.