Abstract

Population growth has led to increased urbanisation, industry, and agricultural operations to supply food demand and these anthropogenic activities causes environmental stress. Using wastewater for irrigation due to lack of fresh water is a major source of heavy metal. This study examined the levels of arsenic in soil and vegetables samples from agricultural areas in Delhi-NCR, India.

The soil and vegetable samples were collected from Okhla region of Delhi. 7 types of different vegetables were collected which includes brinjal, fenugreek leaf, coriander leaf, sem bean, spinach, mustard leaves, chickpea leaves. The soil samples were collected separately for each vegetable then further analysed. The materials were digested using wet digestion techniques on a hot plate before being analysed for arsenic by hydride generating atomic absorption spectrometry.

The concentration of Arsenic in soil exceeds 20 mg/kg above the permissible limit of World Health Organization (WHO) which may lead to a detrimental effect on soil quality, leading to food contamination. Leafy vegetables shows higher concentration of arsenic when compared with tubers and roots. Mean concentration of arsenic in soil is 24.50 mg/kg. The concentration of arsenic were highest in dhaniya and methi samples. It is found that crops with higher water absorption rates accumulate more arsenic. Hazard Quotient based on estimated daily intake was found >1 for arsenic. Hazard quotient due to intake of arsenic in vegetables was >1 with high values of 7.205 mg/kg ,15.078 mg/kg in methi and dhaniya samples, respectively.

To minimise future health hazards, it is advised to monitor heavy metal concentrations in soil and crops in the research region frequently. Secondly, usage of wastewater should be reduced for vegetation. The study implies that continuing the current trend of atmospheric deposition might destabilise sustainable agriculture practices and increase harmful metal consumption in diet.