Abstract:
The effect of cement dust pollution on heavy metal uptake, growth, chlorophyll content, vitamin content and metal accumulation of Celosia argentea (Lagos spinach) was investigated. Loamy soil polluted with Portland cement (100:1) had significant amount of iron, calcium, magnesium, aluminium, silicon and sulphur (in form of sulphates) which are prominent in cement dust. Zinc and copper levels in the polluted soil though not present in cement dust, were also significantly higher in concentration in the polluted soil. The presence of cement in the polluted soil did not affect the germination time of C. argentea seeds. Upon growing, the spinach plants were polluted with 10.2 g mG2 cement dust at 3 days interval, between the 40th and 100th days of their growth. The results showed that cement dust had no significant effect on the germination of seeds of C. argentea. There was a significant reduction in shoot length and total leaf area of polluted plants. The dry weight of the polluted plants was significantly lower throughout the period of analysis than those of the control plants. The frequency and size of the epidermal cells and stomata of the polluted leaves were greatly modified. The level of vitamin A was reduced by 62%, vitamin B2 by 55% and vitamin C by 24%. Though the iron and calcium concentrations of the polluted plants were raised by 78 and 26%, respectively, there was a significant accumulation (at p = 0.05) of heavy metals such as aluminium (Al), copper (Cu) and zinc (Zn) in the polluted plants. These results may discourage the practice of vegetable gardening in areas under cement dust pollution.