A lack of appropriate proxies has traditionally hampered our ability to distinguish riverine organic carbon (OC) sources at the landscape scale.
The major terrestrial OC sources considered here are C3 and C4 vegetation, though it is necessary to account for or dismiss the contribution from autochthonous sources, including phytoplankton, benthic algae and aquatic macrophytes, which in certain conditions can contribute substantially to riverine OC pools in tropical systems (Lewis and others 2001; Davies and others 2008).
Analogous sorption isotherm experiments, with and without fixed Ca concentration, were conducted using citric acid as an OC source.
OC source apportionment indicated a substantial mobile source contribution that was mostly attributable to lubricating oil.
Visits to the ED for CVD were significantly and positively associated with CMB-LGO diesel, gas, biomass burning, and other OC source categories [ Figure 3, Supplemental Material, Table 5 (online at http://www.ehponline.org/members/2008/10873/suppl.pdf)].
No betfair account on my final OC reference, though.
The slight, yet significant (P = 0.001, n = 28), difference in δCPOC between dry season (−22.7 ± 2.0‰, n = 38) and wet season (−21.4 ± 2.3‰, n = 29) suggests that an increasing quantity of riverine OC is sourced from C4 grasslands during the wet season.
A requirement of at least three visits to HSHS, other than the initial health check-up or a visit to a dentist or an ophthalmologist, was set to exclude women who had sought their health care and OCs from other sources.
Radiocarbon (14C) measurements of the total organic carbon were also made to determine the split between the modern and fossil carbon and thereby constrain unknown sources of OC not accounted for by either tracer-based attribution technique.
Menorca is a rural and suburban site with some agricultural activity and no important sources of OC production (Grimalt et al. 2010).
The PM components from road traffic include engine emissions, comprising largely of EC and OC, plus non-exhaust sources that are often characterised by elevated concentrations of transition metals (brake wear [copper, antimony], tyre abrasion [zinc], dust from road surfaces [iron]).
