NWFP Introduction. Government of the North West Frontier Province. Retrieved on

Transcription

1 EFFECTS OF FLUORIDE EMISSIONS FROM BRICK KILNS ON CROPS IN PAKISTAN MUHAMMAD NAUMAN AHMAD Environment Department University of York, UK

2 Peshawar Location Capital of the North-West Frontier Province Elevation 510m Area 2,257 km² Population 2,955,254 (2007) Cultural capital and is about 4000 year old Source: EPA, 2007 NWFP Introduction. Government of the North West Frontier Province. Retrieved on

3 Agriculture in Peshawar Cultivable hectares. area is 74,287 Major crops are maize, wheat rice and sugarcane. Fruit: apple. apricot, plum, pear and The best pear, plum and apricot producing area in Pakistan Most of the land is irrigated by Warsak dam situated to the north west of the city.

4 Brick kiln factories Approx. 450 brick kilns in and around Peshawar City. Single kiln produces 800,000 bricks/month Large amount of rubber to start the fire Also burn low quality coal and used engine oil. Emissions include HCs, CO, SO 2, NOx and dioxins. The increased number of brick kilns have almost doubled local levels of air pollution. Source: EPA,

5 Brick kilns in agricultural areas in Peshawar (Google Earth, 2009)

6 Importance of fluoride One of the most phyto- toxic air pollutants No fluoride pollution study to date in this region of Pakistan Brick kilns can contribute to HF pollution Brick kiln firing Brick kiln in an agricultural area

7 Aims of the study To measure air concentrations of HF in and around Peshawar. To survey the extent of HF damage to agricultural crops. To determine if visible HF symptoms are associated with elevated levels of foliar fluoride. To identify HF sensitive and resistant crops in the region.

8 Field study area in Peshawar (Google Earth, 2010)

9 Air sampling Passive sampler at brick works. Installation of passive samplers for HF at AUP, ARI and brick works area HF measured in spring early summer, and in winter, of Method: Malé Declaration Network, 2007 Passive sampler at ARI.

10 Soil and Wheat sampling Soil samples collected from all the sites from wheat and spinach fields. Wheat grains and spinach leaves were also collected

11 Visible Injury to plants by Air Pollution HF visible injury to crops, vegetables and fruits were observed in the area. Summer crops were highly damaged by HF pollution compared to winter crops at BKF HF affected maize leaf HF affected tomato leaf

12 Visible Injury to Apricot by Air Pollution Early stage Mature stage Typical HF tip burn and marginal necrosis

13 Visible injury to Plum by Air pollution Typical HF tip burn injury Shrinking of the premature plum and scars on mature plum fruit

14 Visible injury to mango leaves

15 Extent of HF injury to local crops Plant species No Injury Little Injury Significant Injury Severe Injury Leaf Injury symptoms Apricot (S)* X Margin & tip burn Mango (S) X Margin & tip burn Plum (S) X Margin & tip burn Peach (S) X Margin & tip burn Tomato (S) X Margin & tip burn Potato (S) (W) X No Injury Onion (S) X No Injury Spinach (S) (W) X No Injury Cucumber (S) X No Injury Sugarcane (S) X Necrotic margins Wheat (W)** X Leaf tip burn Maize (S) X Necrotic margins and leaf tip burn *(S) Summer crops **(W) Winter crops

16 HF concentrations in the air are higher at brick works ughf/m ARI BKF 0.1 bdl bdl bdl bdl Feb Mar Apl May Months HF concentration during spring and summer 2008 bdl: below detection limit of 0.1µg m -3

17 Fluoride contents of fruit leaves in brick kiln fields were significantly higher than in other areas a a 60 ugf/g g (DW) a b b b b b BKF AUP Charsadda 0 Apricot Plum Mango

18 Fluoride content of wheat grain & spinach u g F / K g ( D W ) a Spinach F Content b BKF Control m g F /K g ( D W ) a b b BKF ARI AUP Locations Fluoride content of wheat grains and spinach leaves in brick kiln area was significantly higher than at other sites.

19 Fluoride content of soil 7 6 b ab mg gf/kg(dw) a a b ab Water Sol-F Cal Sol-F 1 0 ARI AUP BKF Locations Water and CaCl 2 extracted fluoride content of soil at the brick kiln area did not differ significantly from that at other sites

20 Overall Conclusions HF emissions from brick kilns are a threat to arable crops and fruit trees in Peshawar. F analysis confirmed the foliar injury is due to HF. Visible injury most likely due to direct exposure to HF rather than soil fluorides Further risk assessment of HF exposure throughout around the year is needed, including economic effects on farmers and risk to cattle and humans.

21 Acknowledgments Professor Mike Ashmore Dr. Lisa Emberson Dr Patrick Bueker Dr. Leon van den Berg Regional Air Pollution in Developing Countries (RAPIDC)