Spatial Distribution and Temporal Trends of Polycyclic Aromatic Hydrocarbons (PAHs) in Sediments from Lake Maryut, Alexandria, Egypt

Abstract

Surface and core sediments from Lake Maryut, Egypt, one of the most polluted lakes in Egypt, were analyzed for polycyclic aromatic hydrocarbons (PAHs) using gas chromatography-mass spectrometry. This investigation represents the first extensive study of the distribution and sources of PAHs in sediments from Lake Maryut. The total PAHs concentrations (sum of 39 PAH compounds) in surface sediments varied greatly depending on the sampling location and ranged from 106 to 57,800 ng/g dry weight with a mean concentration of 6,950 ng/g. The most polluted areas are distributed in areas which are mainly influenced by municipal sewage and industrial effluent discharges, suggesting a direct influence of these sources on the pollutant distribution patterns. PAH concentrations were one to two orders of magnitude higher in comparison with those reported for riverine/ estuaries systems around the world. Molecular indices, such as pyrogenic index (PI), methylphenanthrenes to phenanthrene ratio, HMW PAH /LMW PAH , A-PAHs/PPAHs, FL/FL+PY, BaP/BaP+C, IP/IP+BgP, and Per/ ∑(penta-aromatics) were calculated to evaluate different hydrocarbon origins and their relative importance. In general, sediments from the main basin and northwest basin of Lake Maryut showed the highest PAH concentrations with petrogenic signatures, indicating major sources of petrogenic PAHs in the city. On the other hand, lower levels of PAHs with a pyrogenic signature were widely recorded in areas that are distant from anthropogenic sources. At other locations, both petrogenic and pyrogenic inputs were significant. The concentrations of perylene relative to the penta-aromatic isomers are dominant especially in locations associated with terrestrial inputs and in the deepest core sediments, indicating diagenetic origin for the presence of perylene. Temporal trends of PAH concentrations in both cores sediments were influenced by input pathways and followed the economic development and the environmental policies of the Egyptian Government in the last 15 years. Finally, PAH levels in sediments were compared with Sediments Quality Guidelines (effects range median-effects range low) for evaluation probable toxic effects on organism. Results suggest an ecotoxicological risk for benthic organisms mainly in the main basin area, where high concentrations of PAHs were found in sediments influenced by anthropogenic activities.

A 60-year historical record of polycyclic aromatic hydrocarbons (PAHs) pollution in lake sediment from Guangxi Province, Southern China

“…Previous studies (Barakat et al 2011;Keshavarzifard et al 2014;Tobiszewski and Namieśnik 2012) suggested that molecular diagnostic ratios of specific PAHs could be used as independent indicators to identify a more specific origin of PAHs compounds in the environment, because the ratios change with the change in composition and burning temperature of organic matter (Meyers and Ishiwatari 1993). Here we calculated and used the ratios of BaP/(BaP + Chr) versus Fluo /( Fluo + Pyr) (Fig.…”

“…5A) and Ip/(Ip + BghiP) versus Fluo /(Fluo + Pyr) (Fig. 5B) respectively, in order to provide more information about the source appointment of the sediment PAHs at the site (Barakat et al 2011).…”

A Chemical Synthesis of Benzo[a]pyrene Hapten and Its Application in a Streptavidin-Horseradish Peroxidase-Based Enzyme-Linked Immunological Analysis

“…Polycyclic aromatic hydrocarbons (PAHs) are persistent organic pollutants that contain 2-8 aromatic rings in linear, angular, or cluster arrangements [1]. Due to their toxicity and carcinogenicity, PAHs have attracted the attention of environmental chemists and regulatory agencies for several decades [2,3].…”

Sedimentary Record of Polycyclic Aromatic Hydrocarbons from the Shuanglong Catchment, Southwest China

“…Most PAHs corresponded to the development of industrialization and urbanization. Thus, the profile distribution of PAHs in the sediments could elucidate the relationship between the historical trends of PAHs pollution and the socioeconomic development [42][43][44][45]. Many studies have focused on the temporal trends of PAHs in the sediments [16,46].…”