Nharingo Tichaona, Ndumo Tafungwa, Moyo Mambo
Midlands State University, P Bag 9055, Senka Gweru, Zimbabwe.
Environ Monit Assess. 2015 Dec;187(12):738. doi: 10.1007/s10661-015-4974-8. Epub 2015 Nov 10.
The levels and sources of toxic heavy metals in Amanita loosii (AL) and Cantharellus floridulus (CF) mushrooms and their substrates were studied in some parts of Zimbabwe, Rail Block forest (mining town), Macheke forest (commercial farming), and Muganyi communal lands. The mushrooms and their associated soils were acid digested prior to Al, Pb, and Zn determination by inductively coupled plasma optical emission spectroscopy. The transfer factors, mushrooms-soil metal correlation coefficients, daily intake rates, weekly intake rates, and target hazard quotients were calculated for each metal. The concentration of Zn, Al and Pb in mushrooms ranged from 1.045 ± 0.028 to 7.568 ± 0.322, 0.025 ± 0.001 to 0.654 ± 0.005, and a maximum of 5.78 ± 0.31 mg/kg, respectively, in all the three sampling areas. The mean heavy metal concentrations among the three sampling areas decreased as follows: Rail Block forest (mining town) > Macheke forest (commercial farming) > Muganyi communal lands for the concentrations in both mushrooms and total concentration in their substrates. C. floridulus accumulated higher concentrations of Al, Zn, and Pb than A. loosii at each site under study. Zn in both AL and CF (Muganyi communal lands) and Pb in AL (Rail Block forest) were absorbed only from the soils, while other sources of contamination were involved elsewhere. The consumption of 300 g of fresh A. loosii and C. floridulus per day by children less than 16 kg harvested from Rail Block forest would cause health problems, while mushrooms from Macheke Forest and Muganyi communal lands were found to be safe for human consumption. Due to non-biodegradability and bioaccumulation abilities of heavy metals, people are discouraged to consume A. loosii and C. floridulus from Rail Block forest for they have significant levels of heavy metals compared to those from Macheke forest and Muganyi communal lands.
在津巴布韦的一些地区,即铁路街区森林(矿业城镇)、马切克森林(商业农场)和穆加尼公共土地,对卢氏鹅膏菌(AL)和佛罗里达鸡油菌(CF)蘑菇及其基质中有毒重金属的含量和来源进行了研究。在通过电感耦合等离子体发射光谱法测定铝、铅和锌之前,先对蘑菇及其相关土壤进行酸消解。计算了每种金属的转移因子、蘑菇 - 土壤金属相关系数、每日摄入量、每周摄入量和目标危害商数。在所有三个采样区域,蘑菇中锌、铝和铅的浓度范围分别为1.045±0.028至7.568±0.322、0.025±0.001至0.654±0.005,最高为5.78±0.31mg/kg。在蘑菇及其基质中的总浓度方面,三个采样区域的平均重金属浓度下降顺序如下:铁路街区森林(矿业城镇)>马切克森林(商业农场)>穆加尼公共土地。在所研究的每个地点,佛罗里达鸡油菌积累的铝、锌和铅浓度都比卢氏鹅膏菌高。卢氏鹅膏菌和佛罗里达鸡油菌(穆加尼公共土地)中的锌以及卢氏鹅膏菌(铁路街区森林)中的铅仅从土壤中吸收,而其他地方则涉及其他污染来源。对于从铁路街区森林采集的体重不足16公斤的儿童,每天食用300克新鲜的卢氏鹅膏菌和佛罗里达鸡油菌会导致健康问题,而发现来自马切克森林和穆加尼公共土地的蘑菇对人类食用是安全的。由于重金属的不可生物降解性和生物累积能力,不鼓励人们食用来自铁路街区森林的卢氏鹅膏菌和佛罗里达鸡油菌,因为与来自马切克森林和穆加尼公共土地的蘑菇相比,它们含有大量重金属。