Arsenic threatens rice production
Cultivation of rice remains a dominant economic activity in rural Bangladesh and is key to sustaining food security. In fact, food self-sufficiency in Bangladesh mostly depends on rice production since rice alone contributes about 70% of the agricultural GDP and 50% of the total agricultural value added. Cultivation of modern rice varieties has been the main wheel of productivity growth in rice in Bangladesh for the last three decades.
Cultivation of irrigated winter season (boro) rice has increased tremendously after 1970s and at present the area under modern boro rice production is about 4.7 million hectares, covering about 44% of the total rice area. Boro is the most vital rice crop for the economy since it alone contributes about 61% of the total rice output. In fact, production of this irrigation dependent rice crop has enabled the country to shift from chronic food shortages towards self-sufficiency in the recent years.
About 57% of the total arable land area is currently irrigated through shallow tube wells (STW). However, much of the shallow groundwater in south-eastern and south-western parts of Bangladesh is naturally contaminated with arsenic, exposing more than 40 million people to unsafe levels of arsenic in drinking water and potentially threatening food security as arsenic is toxic to rice.
Build-up of arsenic in soil associated with the use of arsenic contaminated irrigation water has been shown to lead to elevated levels of arsenic in paddy soils and eventually to rice grains. Arsenic contamination in water and soil can also adversely affect food safety. The arsenic content of lowland or paddy-rice grain is generally much higher than that of upland cereal crops because of the relatively high availability of soil arsenic under reduced conditions.
This arsenic hazard is a great concern for our country since about 25% people in Bangladesh are affected by arsenic contamination due to drinking of arsenic contaminated water from tubewells. Moreover, it is suspected that there will be possible reduction of crop production due to arsenic contamination if the issue remains unattended. The country cannot afford these adverse effects since it is already struggling to meet the ever-increasing food requirement for her increasing population.
Arsenic contaminated groundwater is the main source of drinking water for about 90% of the total population of Bangladesh (WHO, 2001), and an estimated 40 million people are at risk. High concentration of arsenic has been found in groundwater from thousands of hand tubewells (HTWs) under 60 out of 64 districts across the country. The groundwater in these districts is reported to be contaminated to various degrees, and several million people may be at some health risk due to the ingestion of this contaminated water (Huq and Naidu, 2001 and Ghani et al, 2004).
However, the adverse impact of arsenic contamination of ground water has been categorised as being both primary and secondary by Khuda (2001). The primary impact is on the health of individuals who are exposed to arsenic poisoning through drinking ground water laced with arsenic. After several years of low-level arsenic exposure, skin lesions appear. These are manifested through different symptoms -- dark spots, white spot, keratoses of hands and feet etc.
The secondary impact is an outcome of the primary impact and is reflected in the socioeconomic consequences like inability to do productive works, social exclusion, problems of getting married etc. Therefore, it appears from the available evidence that arsenic contamination in water and in crops is going to be a threat to the lives of hundreds and hundreds of the inhabitants in different locations of the country.
A case study was carried out by the researchers of the agricultural economics division of BRRI on a family at Ashrafpur village in Kachua upazila under Chandpur district.
Mrs. Nasima Khatun is about 45 years old. She is a widow with four children. Her husband was a farmer and had 70 decimal lands. He used to be a part-tenant farmer and continued farming through renting other's land. He also used to work as a petty contractor.
Nasima Khatun belonged to a well-off family. Her husband was an elected member of the Union Parishad. They used to drink tubewell water, which was identified by the local government engineering department (LGED) in 2000 as being arsenic contaminated. Unfortunately, her husband was affected by arsenicosis in1995, and became very sick due to arsenic related illness.
Due to prolonged ailment he eventually lost his working ability. His wife sold their assets, including croplands, for bearing the medical expenses. Ultimately, the family became landless. He died in December, 2004 at the age of 50. His elder son is a rickshaw puller, and his second son is an agricultural labourer. The two elder sons have separate families. Two younger sons are working in a shop as salesmen. The widow and her sons are now suffering from arsenicosis. She and her youngest two sons live together.
Their livelihood depends on the earnings of her youngest son. She also works as a
maidservant occasionally. She cannot work properly due to her ailment. Very often, she suffers from fever and pain. Since her husband was a village leader and petty contractor, she had a solvent family with good social position. But the arsenic related problems made her family helpless and severely food unsecured, and now they are passing their days in a miserable condition.
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