Journal article
Cryptic night-time trace metal and metalloid contamination in an intensively cultivated coastal catchment
Environmental Pollution, Vol.276, 116685
2021
PMID: 33636558
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Abstract
Detailed, high resolution time-series observations were performed to investigate sources, diel cycling, natural attenuation, and loadings of dissolved trace metals/metalloids in a subtropical headwater stream draining intensive horticulture in Australia. A transect of ∼3 km away from the source (farms) showed >75% reduction in concentration and loads of most trace elements. Mercury and arsenic had elevated loads downstream relative to other elements. Hourly time-series sampling revealed elevated creek discharge at night, accompanied by elevated nickel, selenium, copper, and mercury loads. Inputs from groundwater or treated sewage used for irrigation within the catchment are likely sources. Groundwater bore and treated sewage samples were highly contaminated with either zinc, copper, or mercury. Comparisons of daily and hourly samples indicated common sampling strategies can underestimate horticultural contaminant loadings. Load estimates for mercury and copper derived from hourly samples were 1.6- to 7- fold greater than loads from daily sample data collected over 79 days with varying rainfall. These high contaminant concentrations and loads are of concern to food products receiving irrigation and protected waterbodies downstream.
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•Metal(loid) fluxes from farm drainage were assessed hourly, after rain, and spatially.•Unexpected discharge of Hg, Cu, Se, and Ni occurred during night hours.•Common sampling methods underestimated contaminant loads by up to >700%.•Treated sewage used in irrigation delivered significant metal(loid)s to catchment soils.•Metal(loid) loads were attenuated naturally, except for Hg and As.
Details
- Title
- Cryptic night-time trace metal and metalloid contamination in an intensively cultivated coastal catchment
- Creators
- Stephen R Conrad (Author) - National Marine Science Centre, Southern Cross University, 2 Bay Dr, Coffs Harbour, 2450, NSW, AustraliaIsaac R Santos (Author) - National Marine Science Centre, Southern Cross University, 2 Bay Dr, Coffs Harbour, 2450, NSW, AustraliaShane A White (Author) - National Marine Science Centre, Southern Cross University, 2 Bay Dr, Coffs Harbour, 2450, NSW, AustraliaRebecca L Woodrow (Author) - National Marine Science Centre, Southern Cross University, 2 Bay Dr, Coffs Harbour, 2450, NSW, AustraliaChristian J Sanders (Author) - National Marine Science Centre, Southern Cross University, 2 Bay Dr, Coffs Harbour, 2450, NSW, Australia
- Publication Details
- Environmental Pollution, Vol.276, 116685
- Publisher
- Elsevier Ltd
- Identifiers
- 991012922097602368
- Academic Unit
- Faculty of Science and Engineering; National Marine Science Centre; Science; National Centre for Flood Research
- Language
- English
- Resource Type
- Journal article