Growth response, heavy metal content, and health risk assessment of Brassica juncea L. and Amaranthus tricolor L. cultivated in urbanized and rural areas
Urbanization will lead to changes in socioeconomic structures in Malaysia. It may also lead to changes in the quality of agricultural products due to modified ecosystem. The purpose of this study is to observe and to evaluate the plant growth responses and Health Risk Assessment (HRA) on two sele...
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Format: | Thesis |
Language: | English |
Published: |
2019
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Subjects: | |
Online Access: | http://psasir.upm.edu.my/id/eprint/104540/1/SYAMIRA%20BINTI%20RAMLI%20-%20IR.pdf |
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Summary: | Urbanization will lead to changes in socioeconomic structures in Malaysia. It may also
lead to changes in the quality of agricultural products due to modified ecosystem. The
purpose of this study is to observe and to evaluate the plant growth responses and Health
Risk Assessment (HRA) on two selected leafy vegetables. Brassica juncea L. (Brassica
sp.) and Amaranthus tricolor L. (Amaranthus sp.) that were grown under urban
ecosystem at Seksyen 24, Shah Alam and the rural (traditional) Field of UPM were
compared in terms of their growth performance. Growth parameters such as leaf area
ratio (LAR), leaf weight ratio (LWR), and specific leaf area (SLA) were determined from
the dry weight of plants’ parts that had been oven-dried until constant weight was
achieved. Chlorophyll contents were determined using extraction method of fresh leaf in
80% acetone, while photosynthetic parameters (photosynthesis, transpiration rate, and
stomatal conductance) were determined using Portable Photosynthesis System (LI-
6400XT). Heavy metals such as copper (Cu2+), iron (Fe2+), and zinc (Zn2+) were
determined using a dry-ashing method. Health Risk Assessment (HRA) parameters,
Estimated Daily Intake (EDI) and Target Hazard Quotient (THQ) were done according
to the formula. The results showed that total dry weight of Brassica sp. was greater when
grown in rural area, and greater for Amaranthus sp. when grown in urban area. The LAR
values of both species were found to be higher in the samples grown in urban area
compared to rural area. The LWR values of Brassica sp. were higher in the samples
grown in rural area and LWR of Amaranthus sp. were higher when grown in urban area.
The values of SLA were higher in both species grown in urban area compared to rural
area. Meanwhile, the chloropyhll content in Brassica sp. were higher in the samples
grown in rural area. However, the chlorophyll contents in Amaranthus sp. were higher
in the samples grown in urban compared to rural area. All photosynthetic parameters of
both species were higher in the samples grown at rural area compared to urban area.
Meanwhile, the heavy metals were found to be higher in the samples grown in urban area
compared to rural area, except for Zn. HRA assessment showed that no health risk to
human when consuming both vegetables grown from both sites since THQ values were
less than 1. Urbanization has significant changes on some of the physiological reactions
and contamination that occurs in urbanized area may contribute in exposure to health
risk. |
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