The Role of Hydrology in the Polychlorinated Dibenzo-p -dioxin and Dibenzofuran Distributions in a Lowland River

Abstract

Persistent organic pollutants such as polychlorinated dibenzo--dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) are environmental contaminants that have widespread distribution and pose a serious threat to aquatic ecosystems. We conducted a study to quantify the distribution, patterns, and transport of PCDDs and PCDFs along the Pilica River in central Poland under different hydrological conditions to estimate the loads of these compounds and understand their fate in aquatic systems. Water samples were collected at five sampling points along the river that represent a range of hydrological conditions including flooding and stable and low water flows. Reduced river water flow was associated with lower average total and toxic equivalent (TEQ) concentrations of PCDDs plus PCDFs: 33.6 pg L and 4.21 pg TEQ L for flooding; 28.3 pg L and 3.6 pg TEQ L for stable flow; 18.4 pg L and 1.0 pg TEQ L for low-water flow. Similar results were observed for daily loadings of total and TEQ concentrations: the highest values were observed during flooding (331.1-839.4 mg d and 27.8-110.7 mg TEQ d), medium under stable hydrological conditions (55.8-121.0 mg d and 7.7-15.3 mg TEQ d), and the lowest values during low water flow (30.9 and 40.3 mg d and 1.4-2.4 mg TEQ d). The results demonstrate that diffuse sources of pollution play a key role during periods of high water flow (i.e., flooding season), whereas point sources of pollution, including municipal and industrial wastewater treatment plant discharges, mainly determine the PCDD and PCDF concentrations seen during low water periods.

The use of a hybrid Sequential Biofiltration System for the improvement of nutrient removal and PCB control in municipal wastewater

“…What is more, the plethora of data demonstrates that WWTPs are not efficient at removing PCBs 11–15, 17 . Consequently, these compounds are detected not only in raw and treated wastewater, but also in rivers 7, 8, 59 , thus posing a threat to the whole river ecosystem.…”

The impact of environmental pollution on the quality of mother's milk

“…The recent reports suggest that high concentrations of pro-inflammatory cytokines in milk may be connected to inflammation in the child, and their excess in food can be harmful when the newborn has necrotizing enterocolitis (MohanKumar et al 2017 ; Rentea et al 2017 ). Monitoring mother’s milk is very important both in the search for compounds crucial for a developing organism and in testing for potential contaminants—environmental agents which can disrupt developmental process (Table 1 ) such as heavy metals, polychlorinated biphenyls, or dioxins (Rebelo and Caldas 2016 ; Urbaniak et al 2015 ). Persistent organic pollutants such as dioxins and polychlorinated biphenyls are very hard to eliminate from the environment.…”

The Application of Different Biological Remediation Strategies to PCDDs/PCDFs Contaminated Urban Sediments

“…To minimize the inflow of such pollutants to river ecosystems and their further transport along the river continuum, small dam reservoirs, sedimentation ponds and biofilters might be used. These constructions create ideal conditions for the sedimentation and deposition of particulate matter by decreasing the flow velocity, thus acting as efficient traps for associated compounds of urban origin [4][5][6][7][8][9][10][11][12]. However, the accelerated accumulation of sediments and associated pollutants leads to rapid siltation of such constructions, and this requires periodical dredging of the accumulated sediments and their further utilization [7].…”

“…Nevertheless, urban sediments also contain other compounds with harmful properties, such as heavy metals, pesticides washed out from urban green areas, car oils from streets and parking areas, and a variety of other organic compounds of industrial or anthropogenic origin. One of the most toxic groups of compounds, which have carcinogenic, hepatotoxic, immunotoxic and neurotoxic properties, are polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDDs/PCDFs) [9,10]. These pollutants are characterized by a wide range of occurrence in the urban water ecosystems, because their main source is the load of domestic and industrial wastewater, atmospheric emission and deposition as well as emission from other sources associated with human activity in the city space such as car traffic [10].…”