Halogenated pollutants in terrestrial and aquatic bird eggs: Converging patterns of pollutant profiles, and impacts and risks from high levels
Research Unit: Environmental Sciences and Development, North-West University, Potchefstroom 2520, South Africa; National Metrology Institute of South Africa, Pretoria, South Africa; The Norwegian School of Veterinary Sciences, Oslo, Norway
We investigated the presence, levels, relationships, and risks of HCHs, DDTs, chlordanes, mirex, PCBs, and brominated flame retardants (BFRs) in terrestrial and aquatic bird eggs from an area in South Africa where DDT is used for malaria control. We found one of the highest σDDT levels reported this century; 13. 000. ng/g. wm (wet mass) in Grey Heron eggs which exceeds critical levels for reproductive success (3000. ng/g. wm) calculated for Brown Pelicans, with a no-effect level estimated at 500. ng/g. wm. Even higher σDDT levels at 16. 000. ng/g. wm were found in House Sparrow eggs (possibly the highest ever recorded for sparrows), with a maximum of 24. 400. ng/g. wm. Significant eggshell thinning in Cattle Egrets (33% between thickest and thinnest) was associated with increased levels of p,. p'-DDT and p,. p'-DDE. There were indications of unknown use of DDT and lindane. Relative to DDT, PCBs and BFRs levels were quite low. Ordinated data showed that different terrestrial pollutant profiles converged to a homogenised aquatic profile. Converging profiles, high levels of DDT in heron and sparrow eggs, and thinning eggs shells, indicate risk and impacts at release, in the aquatic environment, and in between. If characteristic life-strategies of birds in warm areas (e.g. longer-lived and fewer eggs per clutch) increases the risk compared with similar birds living in colder regions when both experience the same environmental pollutant levels, then malaria control using DDT probably has more significant impacts on biota than previously realised. Therefore, risk assessment and modelling without hard data may miss crucial impacts and risks, as the chemical use patterns and ecologies in Africa and elsewhere may differ from the conditions and assumptions of existing risk assessment and modelling parameters. Consideration of other findings associated with DDT from the same area (intersex in fish and urogental birth defects in baby boys), together with the findings of this study (high levels of DDT in bird eggs, eggshell thinning in the Cattle Egrets, and the apparent absence of breeding piscivore birds in the sprayed area) are strongly suggestive of negative impacts from DDT spraying for Malaria control. Our data presents strong arguments for an expedited process of replacing DDT with sustainable methods. © 2013 Elsevier Inc.
bromine derivative; chlorphenotane; flame retardant; lindane; mirex; polychlorinated biphenyl derivative; aquatic environment; biota; bird; breeding; data set; DDT; eggshell; HCH; malaria; piscivore; pollutant; reproductive success; risk assessment; air pollutant; aquatic environment; aquatic species; article; birth defect; breeding; egg; egg shell; halogenation; malaria control; nonhuman; Passer domesticus; priority journal; reproductive success; risk assessment; soil pollutant; South Africa; terrestrial species; South Africa; Ardea cinerea; Aves; Bubulcus; Passer domesticus; Passeridae; Pelecanus occidentalis; Bird eggs; DDT; Eggshell thinning; Indoor residual spraying; Malaria control; South Africa; Animals; Birds; Environmental Pollutants; Hydrocarbons, Halogenated; Multivariate Analysis; Ovum; South Africa