Obrázek 13 Obrázek 17 Obrázek 19 Obrázek 20 Obrázek 9 Obrázek 10 Obrázek 11 Obrázek 12 Cadmium and chromium Kristýna Kroupová Modern Methods of Pollutant Analysis Research Centre for Toxic Compounds in the Environment Obrázek 13 Obrázek 17 Obrázek 19 Obrázek 20 Outline •Cadmium and chromium in the environment •Compounds and human exposure •Toxicity •Methods •Legislation •Summary 2 Obrázek 13 Obrázek 17 Obrázek 19 Obrázek 20 Cd and Cr in the environment •Cadmium –Application: •Batteries (Ni-Cd) •Electroplating •Pigments: Cadmium yellow, cadmium red, cadmium orange •Chromium –Application: •stainless steel •Electroplating •Dyes and pigments –Chrome yellow, green –Chromium oxide (green) – main ingredient in infrared reflecting paints •Wood preservative •Tanning (leather) •Catalyst (polyethylene production, water gas shift reaction, hydrogenation) 3 Picture 2 •Naturally in Earth's crust •Natural sources: Volcanic eruptions, erosion •Anthropogenic sources: –mining, industrial wastes, coal combustion, chemical industry, fossil fuels, transportation, fertilisers Obrázek 13 Obrázek 17 Obrázek 19 Obrázek 20 Compounds and human exposure •Cadmium Compounds: Rare in pure state in nature Mostly in oxidation state II+ Inorganic salts Organic compound •microbial formation of monomethyl cadmium (significance not know) Main sources of human exposure: •Eating, drinking, smoking, dust breathing Retains in kidney and liver Biological half-life: 10 – 30 years Excretion: urine, hair, nails, breast milk •Chromium Compounds: oxidation states from –II to +VI. CrIII and VI+ are relevant. CrII, IV+, V+ - short lifetime, CrO2 nontoxic Main sources of human exposure: •Eating, drinking: Higher concentrations in food from stainless steel cans. •Dust breathing – small amounts, smoking •Household goods: wood preservatives, cement, textiles, leather products. Retains mostly in kidneys and lungs. CrIII unable to cross cell membrane CrIV cross cell membranes through phosphate and sulfate anion-exchange carrier pathway. Biological half-life: varies from 15 days to 5 years (depend on form) Excretion: urine, breast milk, hair, nails 4 Obrázek 13 Obrázek 17 Obrázek 19 Obrázek 20 Toxicity 5 •Chromium CrIII essential for mammal's metabolism CrVI: Toxic •irritation of upper respiratory tract and skin •nose bleeding •ulceration •kidney and liver problems •imunotoxic, neurotoxic •IARC carcinogen (Group1) only CrVI –Lung –Upper respiratory tract •Lack of appropriate data on effect of chromium during lactation. Cadmium •renal dysfunction •Long/high exposure – renal failure •Bone demineralization - osteoporosis •Neurotoxic, genotoxic, teratogenic •IARC carcinogen (Group 1) –Lung –Endometrium –Bladder –Breast Obrázek 13 Obrázek 17 Obrázek 19 Obrázek 20 Methods 6 •Chromium Total Cr: UV/VIS photometry, AAS, ICP-MS Cr speciation: 1.separation of species: ion pair chromatography 2.Detection: UV/VIS photometry, AAS, ICP-MS, chemiluminiscence methods… Cadmium Total Cd: ICP-MS, ET-AAS, GF-AAS… Cd speciation: 1.Separation: –Gel permeation chromatography, –Anion-exchange chromatography –HPLC 2.Detection: –AAS –ICP-MS –Voltametry Obrázek 13 Obrázek 17 Obrázek 19 Obrázek 20 Legislation 7 •Chromium limit Emission (suma of metals As, Co, Ni, Se, Tl, Cr) 2 mg/m3 imission - Water 0,025 – 0,5 mg/l Soil 0,29 – 90 mg/kg (dry mater) Food 0,2 – 4,0 mg/kg … Cadmium – limits limit Emission 0,05 mg/m3 Imission (PM10), year average 5 ng/m3 Water (for babies, surface water, waste water…) 5 ug/l – 0,2 mg/l Soil (different type) 0,04 – 800 mg/kg (dry mater) Food (different type) Commission Regulation (EC) No 1881/2006 0,05 – 1,0 mg/kg Toys Directive 2009/48/EC of the European Parliament Many more… Convention on Long-Range Transboundary Air Pollution (CLRTAP): Protocol on Heavy Metals (1998) - The protocol addresses the reduction of cadmium, lead and mercury emissions Obrázek 13 Obrázek 17 Obrázek 19 Obrázek 20 Summary ✓Presence of Cd and Cr in wide range of matrices – possible sources of human exposure ✓Toxicology data available (gaps – effects in small doses and mixtures) ✓Methods (mostly for total concentrations, speciation of Cd and Cr is hard to perform) ✓Legislation ✓ •Future plan: •Methods for speciation in solid samples (Cr) •Methods for speciation Cd and Cr in complex matrixes (content of fat and protein e.g. human tissues – milk, blood, muscles…) •Evaluation of effect during lactation (Cr) •Evaluation of effect in low doses and mixtures 8