Quantitative risk assessment for reclaimed wastewater irrigation on paddy rice field in Korea

Abstract

Water shortage has become an important issue for Korean agriculture. Korea suffers from a limited agricultural water supply, and wastewater reuse has been recommended as an alternative solution. This study examined the concentrations of toxic heavy metals and Escherichia coli in a paddy rice field irrigated with reclaimed wastewater to evaluate the risk to farmers. Most epidemiological studies have been based on upland fields, and therefore may not be directly applicable to paddy fields. In this study, a Beta-Poisson model was used to estimate the microbial risk of pathogen ingestion. The risk value increased significantly after irrigation and precipitation. The results of the microbial risk assessment showed that risk values of groundwater and reclaimed wastewater irrigation were lower than the values of effluent directly from wastewater treatment plants. The monitoring results of heavy metals for each irrigated paddy fields did not show specific tendency. A risk assessment for toxic heavy metals was performed according to various exposure pathways; however, the results of the carcinogenic and noncarcinogenic risk estimation showed that the risk from reclaimed wastewater-irrigated paddy fields was the lowest.

Rice Cultivation without Synthetic Fertilizers and Performance of Microbial Fuel Cells (MFCs) under Continuous Irrigation with Treated Wastewater

“…In addition, irrigation with TWW is advantageous to the improvement of soil fertility and rice productivity while reducing the use of commercial fertilizers [3] as a result of the substantial amounts of plant nutrients such as N, P, K, and organic matter available in TWW. However, these benefits are likely countered by substantial concerns about human health risks, owing to potential pathogenic microorganisms, heavy metals, and other contaminants in wastewater [4,5]. Thus, it is necessary to develop new irrigation management strategies and technologies to optimize the advantages while minimizing the aforementioned downsides.…”

Variation of Polycyclic Aromatic Hydrocarbon (Pah) Contents in the Vadose Zone and Groundwater Under Long‐term Irrigation Using Reclaimed Water

“…Compared with PAHs detected in reclaimed water, Ace, Fl and Ant which existed in reclaimed water were not detected in the 0–600 cm soil profiles. This may be explained by their low concentrations in reclaimed water and easy biodegradability as low‐ring PAHs (Rhee et al, ). In addition, BaA and Chr which were not detected in the reclaimed water were detected in the 0–600 cm soil profiles.…”

Municipal Wastewater Irrigation for Rice Cultivation

“…A study conducted in a province in northern Vietnam [29] assessed the risk of skin disease among farmers occupationally exposed to wastewater, showing that exposure to wastewater is a major risk factor for skin disease, but it is not clear which chemical and biological agents might play the main role in causing the diseases. Rhee et al [30] examined the concentrations of E. coli in a paddy rice field irrigated with reclaimed wastewater and evaluated the risk of its infection among farmers using beta-Poisson doseresponse model. The results showed that the risk was lower in irrigation of groundwater and reclaimed wastewater irrigation than in irrigation of direct effluent from wastewater treatment plant.…”

“…Irrigated rice cultivation makes up 55% of harvested rice area and contributes to 75% of global rice production [19]. Irrigation of rice paddy using treated or untreated wastewater is extensively practiced and examined in many countries to investigate benefits [20][21][22][23][24][25][26] or drawbacks of the practices [12,[27][28][29][30][31][32][33].…”