Displaying publications 1 - 20 of 31 in total

Abstract:
Sort:
  1. Shuhaimi-Othman M, Pascoe D
    Ecotoxicol Environ Saf, 2007 Jan;66(1):29-35.
    PMID: 16647753
    The uptake and elimination of copper (Cu), cadmium (Cd), and zinc (Zn) by the amphipod Hyalella azteca during exposure to the metals singly and in various combinations was examined in controlled laboratory experiments. In single metal exposures the accumulation of all metals was rapid and increased with exposure time. Copper elimination was slower compared to that for zinc and for cadmium no elimination was detected after 5 days in clean water. In the two-metal mixtures it appears that the presence of one metal influenced the bioconcentration of the other, since the bioconcentration factor (BCF) for copper was higher in the presence of cadmium than in the presence of zinc and in the case of cadmium, the decrease of K(1) values from cadmium single exposure to the binary and tertiary mixtures suggests possible inhibition of cadmium uptake by the other metals. In the case of the three-metal mixture the situation is less clear, with both increased and decreased BCFs recorded, in comparison to single-metal and two-metal mixtures, suggesting both stimulation and inhibition of metal accumulation.
  2. Shuhaimi-Othman M, Lim E
    Sains Malaysiana, 2006;35:29-34.
    Satu kajian kualiti air di Tasik Chini telah dijalankan pada bulan Julai, Ogos dan September 2004. Sebanyak 15 stesen persampelan telah dipilih dan sebanyak 14 parameter kualiti air telah ditentukan dalam kajian ini. Keputusan yang diperolehi menunjukkan nilai purata keseluruhan tasik bagi tiga bulan persampelan bagi parameter suhu, oksigen terlarut, konduktiviti, jumlah pepejal terlarut, turbiditi, ph, ammonia-N, nitrat, fosfat, permintaan oksigen kimia, sulfat, permintaan oksigen biokimia dan jumlah pepejal terampai masing-masing adalah 29.73 ± 0.44 °C, 6.08 ± 0.88 mg/L, 21.35 ± 4.32 mS/cm, 13.66 ± 2.76 mg/L, 2.84 ± 3.77 NTU, 6.63 ± 0.24, 0.11 ± 0.04 mg/L, 0.02 ± 0.02 mg/L, 0.05 ± 0.02 mg/L, 0.23 ± 0.36 mg/L, 16.69 ± 4.31 mg/L, 1.97 ± 1.32 mg/L dan 5.17 ± 3.67 mg/L. Perbandingan dengan nilai Piawaian Interim Kualiti Air Kebangsaan (INWQS) menunjukkan secara amnya parameter yang dikaji berada dalam kelas I-IV. Kepekatan klorofil-a adalah rendah pada bulan Julai dan September dengan purata 1.4 µg/L, tetapi meningkat pada bulan Ogos dengan purata 21.91 µg/L dan meletakkan Tasik Chini dalam status eutrofik pada bulan tersebut. Faktor-faktor yang menyumbang ke arah fenomena in dibincang lanjut dalam kertas ini.
  3. Shuhaimi-Othman M, Nurul-Akhma Z, Azmah M
    Sains Malaysiana, 2012;41:573-583.
    Biomonitor Multispesies Air Tawar (MFB™) digunakan bagi mengukur dan menganalisis pelbagai kelakuan daripada pelbagai jenis organisma akuatik untuk memantau kualiti air dalam ekosistem air tawar. Isyarat gerak balas udang air tawar (Macrobrachium lanchesteri) dan ikan gapi (Poecilia reticulata) dikaji di dalam makmal bagi menentukan respons yang spesifik terhadap pendedahan kepekatan air larut resap yang berbeza (1%, 3% dan 5%) bagi kedua-dua organisma. Perubahan perilaku organisma (pergerakan dan ventilasi) direkodkan dengan menggunakan Biomonitor Multispesies Air Tawar (MFB) selama 24 jam. Hasil yang diperoleh menunjukkan terdapat trend peningkatan respons pergerakan dan ventilasi yang jelas dengan peningkatan kepekatan pendedahan air larut resap bagi udang air tawar. Manakala respons yang ditunjukkan oleh ikan gapi adalah tidak begitu jelas walaupun terdapat trend pengurangan pergerakan dengan peningkatan kepekatan pendedahan air larut resap dan trend peningkatan ventilasi dengan peningkatan kepekatan pendedahan. Kajian ini menunjukkan M. lanchesteri memberikan respons yang lebih sensitif kepada air larut resap berbanding P. reticulata dan organisma ini lebih sesuai digunakan sebagai organisma penunjuk untuk MFB.
  4. Ahmad A, Mushrifah I, Mohamad Shuhaimi-Othman
    A study on water quality and heavy metal concentration in sediment at selected sites of Sungai Kelantan was carried out. Ten water samples were collected along the river for physical and chemical analysis and twenty-six water and sediment samples were collected for heavy metal analysis. Water was sampled at three different dates throughout the study period whereas sediments were collected once. In addition to heavy metal analysis, sediment samples were also analysed for texture, pH and organic content. The physical and chemical water quality analyses were carried out according to the APHA procedures. Result of water quality analysis (physico-chemical) indicated that Sungai Kelantan is characterised by excellent water quality and comparable to pristine ecosystems such as the National Park and Kenyir Lake. This river was classified into class I – class III based on Malaysian interim water quality standard criteria (INWQS). Heavy metals Pb, Zn, Cu and Cd was detected at low concentration in sediment samples, except for Fe and Mn. The presence of Fe and Mn in sediment samples was though to be of natural origin from the soil. Anthropogenic metal concentrations in sediment were low indicating that Sungai Kelantan has not experienced extreme pollution.
  5. Shuhaimi-Othman M, Azmah M, Ahmad A
    Biomonitor Multispesies Air Tawar (Multispecies Freshwater Biomonitor®) (MFB) menggunakan pengukuran dan analisis pelbagai kelakuan daripada pelbagai jenis organisma akuatik untuk memantau kualiti air dalam ekosistem air tawar. Kajian ini dijalankan di dalam makmal bagi menentukan respons spesifik udang air tawar (Macrobrachium lanchesteri) dan ikan gapi (Poecilia reticulata) terhadap logam berat kadmium (Cd). Kepekatan Cd yang berbeza didedahkan kepada M. lanchesteri (1 ppb dan 10 ppb) dan P. reticulata (100 ppb dan 560 ppb) dan perubahan perilaku setiap organisma direkod dengan MFB selama 2 jam. Hasil yang diperolehi menunjukkan peningkatan respons pergerakan dan ventilasi udang air tawar dan ikan dengan peningkatan kepekatan pendedahan kepada logam Cd. Kajian ini menunjukkan udang memberi respons yang lebih sensitif kepada logam Cd berbanding ikan gapi dan spesies tempatan ini sesuai digunakan sebagai organisma penunjuk untuk MFB.
  6. Shuhaimi-Othman M, Ahmad A, Norziana G
    Kajian kepekatan logam dalam air di Tasik Bukit Merah telah dijalankan pada April 2009. Lima belas stesen persampelan telah dipilih dan sampel air permukaan bagi penentuan logam telah diambil. Beberapa parameter kualiti air seperti suhu, konduktiviti, oksigen terlarut, pH dan keliatan air telah ditentukan di setiap stesen. Sebanyak 11 jenis logam iaitu kadmium, zink, plumbum, kuprum, nikel, ferum, kobalt, aluminium, barium, kromium dan mangan (Mn) telah ditentukan dalam sampel air. Keputusan menunjukkan kepekatan semua logam kajian berada di bawah kepekatan maksimum yang dicadangkan oleh piawaian Malaysia dan antarabangsa bagi melindungi hidupan akuatik kecuali bagi logam Fe dan Al. Bagi parameter kualiti air, kajian menunjukkan semua parameter berada dalam julat kepekatan semula jadi (kelas I) berdasarkan Piawaian Kualiti Air Kebangsaan (NWQS Malaysia) kecuali oksigen terlarut dan pH di beberapa stesen persampelan terutama di bahagian timur tasik yang didapati dipengaruhi oleh faktor-faktor semula jadi dan antropogenik.
  7. Abduljaleel SA, Shuhaimi-Othman M
    Pak J Biol Sci, 2013 Nov 15;16(22):1551-6.
    PMID: 24511699
    The influence of dietary cadmium on the accumulation and effects of dietary lead, examined in chicken. This experiment was conducted to investigate the toxic effects of dietary Cd and Pb on chick's body weight and organ, content of the tissues of these two metals was also detected. One day age chicks of Gallus gallus domesticus fed diet supplemented with 25, 50, 100 ppm of Cd, second group exposure to 300, 500, 1000 ppm of Pb in feed daily during 4 weeks. The control groups were fed without supplementation of metals. The concentrations of Cd and Pb resulted in increased of Cd and Pb content in liver, gizzard and muscle. While Cd 100 ppm and Pb 1000 ppm were increased metals content in feather. Body weight of chicks was not influenced by Cd treatment. In contrary Pb treatment was significantly (p < 0.05) decreased body weight of chicks after dietary treatment. On the other hand, Liver weigh in chicks was significantly (p < 0.05) decreased after Cd and Pb treatments.
  8. Shuhaimi-Othman M, Nur-Amalina R, Nadzifah Y
    ScientificWorldJournal, 2012;2012:125785.
    PMID: 22666089 DOI: 10.1100/2012/125785
    Adult freshwater snails Melanoides tuberculata (Gastropod, Thiaridae) were exposed for a four-day period in laboratory conditions to a range of copper (Cu), cadmium (Cd), zinc (Zn), lead (Pb), nickel (Ni), iron (Fe), aluminium (Al), and manganese (Mn) concentrations. Mortality was assessed and median lethal times (LT₅₀) and concentrations (LC₅₀) were calculated. LT₅₀ and LC₅₀ increased with the decrease in mean exposure concentrations and times, respectively, for all metals. The LC(50) values for the 96-hour exposures to Cu, Cd, Zn, Pb, Ni, Fe, Al, and Mn were 0.14, 1.49, 3.90, 6.82, 8.46, 8.49, 68.23, and 45.59 mg L⁻¹, respectively. Cu was the most toxic metal to M. tuberculata, followed by Cd, Zn, Pb, Ni, Fe, Mn, and Al (Cu > Cd > Zn > Pb > Ni > Fe > Mn > Al). Metals bioconcentration in M. tuberculata increases with exposure to increasing concentrations and Cu has the highest accumulation (concentration factor) in the soft tissues. A comparison of LC₅₀ values for metals for this species with those for other freshwater gastropods reveals that M. tuberculata is equally sensitive to metals.
  9. Mohti A, Shuhaimi-Othman M, Gerhardt A
    J Environ Monit, 2012 Sep;14(9):2505-11.
    PMID: 22868673 DOI: 10.1039/c2em10902f
    The behavioral responses of guppy Poecilia reticulata (Poeciliidae) and prawn Macrobrachium lanchesteri (Palaemonidae) individuals exposed to acid mine drainage (AMD) were monitored online in the laboratory with a Multispecies Freshwater Biomonitor™ (MFB). These responses were compared to those to reference water acidified to the respective pH values (ACID). Test animals in the juvenile stage were used for both species and were exposed to AMD and ACID for 24 hours. The stress behaviors of both test animals consisted mainly of decreased activity in AMD and increased activity in ACID, indicating that the metals in the AMD played a role as a stress factor in addition to pH. The locomotor activity levels of guppies and prawns for the ACID treatment were higher than the locomotor activity levels for the AMD treatment with increasing pH value. For guppies, significant differences were observed when specimens were exposed to AMD and ACID at pH 5.0 and 6.0; the percentage activities were only 16% and 12%, respectively, for AMD treatment, whereas for ACID treatment, the percentage activities were 35% and 40%, respectively, similar to the value of 36% for the controls. Similar trends were also observed for prawns, for which the percentage activities were only 6% and 4%, respectively, for AMD treatment, whereas for ACID treatment, the percentage activities were 31% and 38%, respectively, compared to 44% in the controls. This study showed that both species are suitable for use as indicators for ecotoxicity testing with the MFB.
  10. Bashir FA, Shuhaimi-Othman M, Mazlan AG
    J Environ Public Health, 2012;2012:352309.
    PMID: 22046193 DOI: 10.1155/2012/352309
    This study is focused on evaluating the trace metal levels in water and tissues of two commercial fish species Arius thalassinus and Pennahia anea that were collected from Kapar and Mersing coastal waters. The concentrations of Fe, Zn, Al, As, Cd and Pb in these coastal waters and muscle, liver and gills tissues of the fishes were quantified. The relationship among the metal concentrations and the height and weight of the two species were also examined. Generally, the iron has the highest concentrations in both water and the fish species. However, Cd in both coastal waters showed high levels exceeding the international standards. The metal level concentration in the sample fishes are in the descending order livers > gills > muscles. A positive association between the trace metal concentrations and weight and length of the sample fishes was investigated. Fortunately the level of these metal concentrations in fish has not exceeded the permitted level of Malaysian and international standards.
  11. Shuhaimi-Othman M, Lim EC, Mushrifah I
    Environ Monit Assess, 2007 Aug;131(1-3):279-92.
    PMID: 17171269
    A study of the water quality changes of Chini Lake was conducted for 12 months, which began in May 2004 and ended in April 2005. Fifteen sampling stations were selected representing the open water body in the lake. A total of 14 water quality parameters were measured and Malaysian Department of Environment Water Quality Index (DOE-WQI) was calculated and classified according to the Interim National Water Quality Standard, Malaysia (INWQS). The physical and chemical variables were temperature, dissolved oxygen (DO), conductivity, pH, total dissolved solid (TDS), turbidity, chlorophyll-a, biochemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solid (TSS), ammonia-N, nitrate, phosphate and sulphate. Results show that base on Malaysian WQI, the water in Chini Lake is classified as class II, which is suitable for recreational activities and allows body contact. With respect to the Interim National Water Quality Standard (INWQS), temperature was within the normal range, conductivity, TSS, nitrate, sulphate and TDS are categorized under class I. Parameters for DO, pH, turbidity, BOD, COD and ammonia-N are categorized under class II. Comparison with eutrophic status indicates that chlorophyll-a concentration in the lake was in mesotrophic condition. In general water quality in Chini Lake varied temporally and spatially, and the most affected water quality parameters were TSS, turbidity, chlorophyll-a, sulphate, DO, ammonia-N, pH and conductivity.
  12. Fawaz Al-badaii, Azhar Abdul Halim, Mohammad Shuhaimi-othman
    Sains Malaysiana, 2016;45:841-852.
    The study to determine the concentrations of dissolved heavy metals in the Sungai Semenyih and to use the environmetric
    methods to evaluate the influence of different pollution sources on heavy metals concentrations was carried out. Cluster
    analysis (CA) classified 8 sampling stations into two clusters based on the similarity of sampling stations characteristics,
    cluster 1 included stations 1, 2, 3 and 4 (low pollution area), whereas cluster 2 comprised of stations 5, 6, 7 and 8
    (high pollution area). Principal component analysis (PCA) of the two datasets yield two factors for low pollution area
    and three factors for the high pollution area at Eigenvalues >1, representing 92.544% and 100% of the total variance
    in each heavy metals data sets and allowed to gather selected heavy metals based on the anthropogenic and lithologic
    sources of contamination.
  13. Ahmad A, Siti Hafizah A, M. Shuhaimi-Othman
    Sains Malaysiana, 2015;44:663-670.
    Suatu kajian telah dijalankan untuk menentukan potensi makroinvertebrat bentik sebagai penunjuk biologi di hulu Sungai
    Ikan, Terengganu. Sebanyak lima stesen pensampelan telah dipilih untuk pensampelan makroinvertebrat bentik dan
    analisis kualiti air. Pensampelan makroinvertebrat bentik telah dilakukan menggunakan jaring Surber dan analisis
    kualiti air dilakukan menurut kaedah APHA. Piawaian Kualiti Air Kebangsaan (NWQS) telah digunakan untuk menilai
    parameter kualiti air di kawasan kajian dan hasil menunjukkan Sungai Ikan berada dalam keadaan baik iaitu kelas I
    hingga II. Ujian ANOVA satu hala menunjukkan bahawa kesemua parameter air yang diuji adalah seragam di sepanjang
    kawasan kajian (p>0.05, α=0.05). Sebanyak 2 filum, 3 kelas, 8 order, 39 famili dan 1353 individu telah dikenal pasti dan
    didominasi oleh famili Baetidae, Siphlonuridae, Simuliidae, Chironomidae dan Elmidae. Famili dominan didapati hadir
    pada hampir kesemua stesen pensampelan. Memandangkan kualiti air adalah baik dan tidak berubah sepanjang kawasan
    kajian, ujian CCA dilakukan untuk memperlihatkan faktor persekitaran lain yang mempengaruhi sebaran makroinvertebrat
    terutamanya famili dominan. Hasil ujian CCA menunjukkan pengaruh persekitaran yang khusus terhadap famili tertentu
    dan mempunyai pengaruh yang kuat terhadap sebaran makroinvertebrat bentik. Ujian korelasi menunjukkan batuan
    besar mempunyai pengaruh besar terhadap sebaran famili Baetidae, Siphlonuridae dan sub-famili Orthocladiinae,
    manakala komposisi pasir pula mempunyai pengaruh terhadap famili Elmidae. Hasil kajian ini menunjukkan dalam
    ekosistem yang bersih, faktor persekitaran habitat adalah kritikal untuk diambil kira dalam menentukan taksa tertentu
    yang sesuai digunakan sebagai penunjuk biologi ekosistem sungai rekreasi.
  14. Shuhaimi Othman M, Nadzifah Y, Nur Amalina R, Ahmad A
    Macrobrachium lanchesteri dewasa telah didedahkan selama empat hari di dalam makmal kepada satu siri kepekatan logam kuprum (Cu) dan nikel (Ni). Masa kematian median (LT50) dan kepekatan kematian median (LC50) dikira berdasarkan data kematian yang diperolehi. Di akhir hari yang ke-4, udang yang masih hidup digunakan untuk penentuan biopemekatan logam. Nilai LT50 dan LC50 didapati meningkat dengan pengurangan kepekatan dan masa pendedahan bagi kedua-dua logam (Cu dan Ni). Nilai LC50 untuk 24, 48 dan 96 jam bagi Cu masing-masing adalah 261.6, 171.6 dan 32.3 μg/L dan bagi Ni 30786.3, 28534.7 dan 8056.6 μg/L. Biopemekatan logam Cu dan Ni oleh M. lanchesteri meningkat dengan peningkatan kepekatan pendedahan dan logam Cu didapati lebih toksik terhadap M. lanchesteri berbanding logam Ni.
  15. Ahmad A, Abd. Aziz Z, Shuhaimi-Othman M
    Sains Malaysiana, 2014;43:1657-1663.
    A study on the chironomids (Diptera:Chironomidae) diversity at pristine ecosystem was carried out at upstream of Sungai Langat, Selangor. The study determines chironomids distribution and composition at 7 streams and river within the upstream site of Langat Catchment. Chironomid was sampled using Surber net and water quality was measured based on Malaysia WQI. The result indicated that Chironomidae was represented by three subfamilies namely Chironominae, Orthocladiinae and Tanypodinae, which comprises of 2502 individuals. Chironominae was the most dominant subfamily (1619 individuals) followed by Orthocladinae (629 individuals) and Tanypodinae (254 individuals). Polypedilum (subfamily: Chironominae) is the most dominant genus found followed by Rheocricotopus (subfamily: Orthocladiinae), Microtendipes and Cryptochironomus. Polypedilum was abundant in all stations except Sg. Langat 3 which was dominated by Rheocricotopus. Sungai Langat 3 has the highest number of individual (1113) which is (44.5%) from total chironomid individual and followed by Sg. Lolo with 468 individuals that were dominated by Polypedilum.
  16. Ahmad A.M., Shuhaimi Othman, Barzani-Gasim M., Mohd Alwi N.
    A preliminary study was conducted to determine the presence and abundance of aquatic worms in Lake Chini ecosystem, Pahang (Gumum Sea). Samplings were conducted twice in 2000. Water quality analysis was conducted to determine the water quality of the lake at the sampling locations. Results showed that nutrient levels in the water body was low and values for other physical parameters such as temperature, pH and conductivity suggested that Gumum Sea in Lake Chini is free from pollution. According to Malaysian interim river classification (Department of Environment, Malaysia), Lake Chini falls within class I to III which indicates good water quality. Annelida was the most dominant phylum found in the study area, which comprise of two major families namely Naididae and Tubificidae. This phylum contributed about 59% of the total individuals sampled and the rests were Arthropoda and Plathyhelmintes. Naididae was the most dominat family and contributed over 98% of the toal population of aquatic worms present. Dero, Aulophorus, Pristina, Branchiodrilus and Ripistes were amongst the dominant genera and showed good adaptations to the pollution free ecosystem of Lake Chini.
  17. Ahmad A, Shuhaimi Othman M, Lim E, Abd. Aziz Z
    Sains Malaysiana, 2013;42:587-596.
    Satu analisis penentuan parameter kualiti air yang penting untuk penilaian ekosistem cetek telah dilakukan menggunakan kaedah multivariat. Sebanyak 14 parameter kualiti air yang melibatkan komponen biologi, fizik dan kimia telah dikumpulkan setiap bulan selama satu tahun. Data dianalisis menggunakan ujian faktor yang melibatkan tiga proses iaitu mengenal pasti korelasi antara faktor, mengekstrak faktor dan seterusnya melihat kesan gabungan faktor-faktor tersebut. Proses pertama melibatkan pengelompokkan parameter yang berkorelasi kuat ke dalam faktor tersendiri dan mengeluarkan parameter yang mempunyai lebih daripada satu faktor. Analisis pengelasan agglomeratif hierarki (HACA) dan analisis diskriminan (DA) juga dilakukan untuk memperlihatkan kelompokan dan pengaruh faktor terhadap kualiti air tasik. Hasil analisis menunjukkan kualiti air Tasik Chini dipengaruhi oleh lebih daripada satu faktor. Hasil kajian menunjukkan komponen biologi dan kimia (nutrien) mempunyai pengaruh kuat dalam penentuan kualiti air tasik. Parameter berasaskan biologi iaitu BOD5, COD, klorofil a dan kimia (nitrat dan ortofosfat) adalah parameter yang
    penting di Tasik Chini. Ketiga-tiga analisis yang dijalankan menunjukkan kepentingan penentuan komponen biologi dan kimia bagi menentukan kualiti air Tasik Chini.
  18. Dewi Hidayati, Ismail B, Shuhaimi-Othman M, Norela Sulaiman
    Sains Malaysiana, 2018;47:1665-1674.
    LUSI (Lumpur“mud”-Sidoarjo) is the mud volcanic which was initiated by the failed gas drilling exploration activities
    carried out near an urban area. The evaluation of the LUSI mud volcanic emission and its dried mud effects on air pollution
    and human health was carried out from 2011 to 2012. The concentrations of particulate matter (PM2
    .
    5
    ), hazardous
    gases (H2
    S, SO2
    , NO2
    ), volatile organic compounds (VOC): Including total hydrocarbons (THC)), toluene (C6
    H5
    CH3
    ) and
    benzene (C6
    H6
    ) as well as heavy metals (Pb, Cr and Cd) were measured following standard methods. The results showed
    that the average concentration of PM2.5 ranged from 24.0-399.9 μg/m3
    , H2
    S: 1.53-2.92 ppm; SO2
    : 0.021-1.321 ppm and
    NO2
    : 0.007-0.076 ppm. The VOC included total hydrocarbons from 0.57-0.96 ppm, toluene 0.33-0.92 ppm and benzene
    0.33-0.40 ppm. Furthermore, heavy metal concentrations were as follows: Pb 2.6-37.34 μg/m3
    ; Cr 0.14-12.8 μg/m3
    and
    Cd 0.78-4.16 μg/m3
    . LUSI contributed to increased air pollution primarily through H2
    S, SO2 and PM2.5. The Air Quality
    Index (AQI) of PM2.5 (164-217) and SO2
    (235-291) showed that the air quality at the disaster area was ‘very unhealthy’.
    Backward trajectories indicated that the wind direction may have had an impact on the air pollution load.
  19. Shuhaimi-Othman M, Yakub N, Ramle NA, Abas A
    J Toxicol, 2011;2011:136104.
    PMID: 21559091 DOI: 10.1155/2011/136104
    Adults of freshwater ostracod Stenocypris major (Crustacea, Candonidae) were exposed for a four-day period in laboratory conditions to a range of copper (Cu), cadmium (Cd), zinc (Zn), lead (Pb), nickel (Ni), iron (Fe), aluminium (Al), and manganese (Mn) concentrations. Mortality was assessed, and median lethal times (LT(50)) and concentrations (LC(50)) were calculated. LT(50) and LC(50) increased with the decrease in mean exposure concentrations and times, respectively, for all metals. LC(50)s for 96 hours for Cu, Cd, Zn, Pb, Ni, Fe, Al, and Mn were 25.2, 13.1, 1189.8, 526.2, 19743.7, 278.9, 3101.9, and 510.2 μg/L, respectively. Metals bioconcentration in S. major increases with exposure to increasing concentrations, and Cd was the most toxic to S. major, followed by Cu, Fe, Mn, Pb, Zn, Al, and Ni (Cd>Cu>Fe>Mn>Pb>Zn>Al>Ni). Comparison of LC(50) values for metals for this species with those for other freshwater crustacean reveals that S. major is equally or more sensitive to metals than most other tested crustacean.
  20. Shuhaimi-Othman M, Yakub N, Umirah NS, Abas A
    Toxicol Ind Health, 2011 Nov;27(10):879-86.
    PMID: 21402654 DOI: 10.1177/0748233711399318
    Fourth instars larvae of freshwater midge Chironomus javanus (Diptera, Chironomidae) were exposed for a 4-day period in laboratory conditions to a range of copper (Cu), cadmium (Cd), zinc (Zn), lead (Pb), nickel (Ni), iron (Fe), aluminium (Al) and manganese (Mn) concentrations. Mortality was assessed and median lethal concentrations (LC(50)) were calculated. LC(50) increased with the decrease in mean exposure times, for all metals. LC(50)s for 96 hours for Cu, Cd, Zn, Pb, Ni, Fe, Al and Mn were 0.17, 0.06, 5.57, 0.72, 5.32, 0.62, 1.43 and 5.27 mg/L, respectively. Metals bioconcentration in C. javanus increases with exposure to increasing concentrations and Cd was the most toxic to C. javanus, followed by Cu, Fe, Pb, Al, Mn, Zn and Ni (Cd > Cu > Fe > Pb > Al > Mn > Zn > Ni). Comparison of LC(50) values for metals for this species with those for other freshwater midges reveals that C. javanus is equally or more sensitive to metals than most other tested dipteran.
Filters
Contact Us

Please provide feedback to Administrator ([email protected])

External Links