Accumulation of Chromium in Root Tissues of Eichhornia Crassipes (Mart.) Solms. in Cachoeira River - Brazil

Abstract

In the last years metal pollution has become one of the most important environmental problems. Concerning the high toxicity of these elements, both sensitive analytical measurements and methods for the control of the ecosystem are required to reveal and localize metals on organism. Due to high transportations rates and exchange phenomena of sediment bound metals and changes of imission concentrations, the estimation of pollution in aquatic systems like the river Cachoeira is problematic. Recent studies have demonstrated that the river´s water basin is polluted by several metals (M.I.G. Severo, A.H. Oliveira, P. A. O. Mangabeira, M.R.V. Veado, P. Galle and R.B. Souza[1]). Water and sediments samples can only refect momentary concentrations. In this context the use of biomonitoring methods offers the possibility to assess the heavy metals pollution. Secondary Ion mass Spectrometry (SIMS) and Inductively coupled plasma mass spectrometry (ICP-MS) were used to localize chromium in Eichhornia crassipes. The pollution in chromium is bound to the clandestin tannery activity on the basin of the Cachoeira region south of Bahia (Brazil). Measurements were performed with the scanning ion microprobe instrument developed at the University of Chicago (UC-HRL) (Levi-Setti, Chabala, Gavrilov, Espinosa and Le Beau [5]. A focused gallium scanning ion probe is used, in conjunction with an efficient secondary ion mass spectrometry system, to obtain high lateral resolution mass-resolved images of specimen surfaces. Secondary ions were collected and analyzed with a magnetic sector mass spectrometer. Each detected secondary ion is recorded discretely (pulse counting) for further analysis. The SIMS signals are detected by na active film electron multiplier (ETP AF820), operating in the pulse counting mode and capable of accepting count rates up to 50 MHz. The images containing 512 x 512 picture elements from single square raster scans, are stored in digital memory with a KONTRON IMCO image processing system for subsequent analysis.Scanning of the samples to locate chromium is carried out using the 52 Cr + SIMS signal displayed on a CRT, at fields of view 80 and 160 µm wide, when detecting positive ions.

Uncommon Heavy Metals, Metalloids and Their Plant Toxicity: A Review

“…The problem of Cr-bioaccumulation can be very important in the case of industrialexploited algae species, namely Gelidium genus species because of their ability to bioccumulate chromium, especially as Cr (III) salts (Vilar et al, 2007). Accumulation of chromium was also determined in some aquatic and floating plants, such as Eichhornia crassipes (Mangabeira et al, 2004), Hydrocotyle umbellata (Yongpisanphop et al, 2005), or Bacopa monnieri (Shukla et al, 2007), that can be used for wastewater treatment. An important question is about the usage of wetland plants such as Typha sp., Phragmites sp., Scirpus sp.…”

“…Some workers reported that Cr (III) ions are highly stabilized by complex formation with organic molecules, such as proteins (glutathione), carbohydrates (especially pentoses), NAD(P)H, FADH 2 , and probably also with organic acids, and stored in root cell vacuoles in precipitated form or in apoplast in cell walls, which is the reason for restricted mobility of chromium in plants (Mangabeira et al, 2004). Transport of chromium is probably restricted only to vascular tissues.…”

“…Transport of chromium is probably restricted only to vascular tissues. A study utilizing tomato plants (Lycopersicum esculentum, Solanaceae) relieved its restriction to vascular tissues of roots (especially secondary xylem), stems, and leaves with localization inside in vessels, a very limited amount in xylem parenchymatic cells, and no transport to cortex or epidermis of stems or palisade/spongy parenchyma of leaves (Mangabeira et al, 2004). Chromium in vascular tissues is probably complexed with organic acids (Juneja and Prakash, 2005).…”

“…Chromium in vascular tissues is probably complexed with organic acids (Juneja and Prakash, 2005). An association of chromium ions with hydroxyl groups of cell walls is probable and can be the reason for no transport out of vascular tissues (Mangabeira et al, 2004). Studies carried out on important vegetable crops and other plants confirmed the ability of some of them (especially cauliflower, kale, and cabbage) to accumulate chromium (as CrO 2− 4 , less as Cr 3+ ), mostly in their roots with general minimal chromium transport to aerial parts (Zayed et al, 1998a) because of their minimal entry to the vascular tissues (Zayed et al, 1998a).…”

Spatial perspective of hexavalent chromium concentration in superficial waters of the Ciénaga de las Quintas Mangrove Swamp, Cartagena de Indias, Colombia

“…When water quality is estimated in terms of the heavy metal concentrations, it is important that the sampling strategy includes characterizing the spatial variation in the pollutant concentration (Hedger, Atkinson, & Malthus, ; Mwamburi, ; Ouma & Mwamburi, ). Heavy metals can accumulate in high concentrations in animals and vegetable tissues (Marchand et al., ; Olivero‐Verbel et al., ; Palaniappan & Karthikeyan, ) and enter the food chain in multiple ways that can produce progressive toxic impacts attributable to its accumulation in different organs over the life cycle of an organism and long‐term exposure to a contaminated environment (Mangabeira et al., ).…”