Preliminary assessment of risk of ozone impacts to maize (Zea mays) in southern Africa.
Surface ozone concentrations in southern Africa exceed air quality guidelines set to protect agricultural crops. This paper addresses a knowledge gap by performing a preliminary assessment of potential ozone impacts on vegetation in southern African. Maize (Zea mays L.) is the receptor of interest in the main maize producing countries, i.e. South Africa, Zambia and Zimbabwe. Surface ozone concentrations are estimated for the growing season (October to April) using photochemical modelling. Hourly mean modelled ozone concentrations ranged between 19.7 and 31.2 ppb, while maximums range between 28.9 and 61.9 ppb, and are near 30 ppb over South Africa and Zambia, while in Zimbabwe, they exceed 40 ppb and translate into monthly AOT40 values of over 3,000 ppb h in five of the seven months of the growing season. This study suggests that surface ozone may pose a threat to agricultural production in southern African, particularly in Zimbabwe.
van Tienhoven
Anna Mieke
AM
CSIR Environmentek, PO Box 17001, Congella 4013, Durban, South Africa.
Zunckel
Mark
M
Emberson
Lisa
L
Koosailee
Avishkar
A
Otter
Luanne
L
D002940:Circadian Rhythm; D004784:Environmental Monitoring / Q000379:methods; D008956:Models, Chemical; D010083:Oxidants, Photochemical / Q000032:analysis / Q000633:toxicity*; D010126:Ozone / Q000032:analysis / Q000633:toxicity*; D018570:Risk Assessment / Q000379:methods*; D012621:Seasons; D013019:South Africa; D015024:Zambia; D003313:Zea mays / Q000187:drug effects*; D015030:Zimbabwe
D010083:Oxidants, Photochemical; D010126:Ozone