Mercury (Hg) pollution from artisanal and small-scale gold mining (ASGM) is a global environmental and public health concern. In Indonesia, ASGM remains widespread, yet assessments of multimedia contamination and health risks are limited. This study quantified Hg concentration in water, sediment, soil, fish, and cassava to evaluate environmental pollution and potential health risks in Waluran, Sukabumi, Indonesia. Mercury concentration in ASGM was higher than in the reference area, especially in fish (median: 4.76 mg/kg dw), cassava leaves (median: 15.7 mg/kg dw), and tailing sediments (median: 171 mg/kg dw). A remarkably high Hg concentration (9760 mg/kg dw) was detected in soil from amalgam-burning spots. An elevated Hg concentration was observed in the reference area, suggesting widespread contamination and potential for long-range dispersion. Over 85% of ASGM samples were categorized as heavily to extremely contaminated by the geo-accumulation index (I_geo). Bioaccumulation assessment indicated a high bioconcentration factor (BCF) in fish and moderate bioaccumulation factor (BAF) in cassava roots. Hazard Quotients (HQ) were greater than 1 for most exposure pathways in both adults and children, with the greatest risk deriving from cassava leaf consumption. These findings indicate severe Hg contamination within ASGM-affected communities and underscore the urgent need for public health interventions, environmental monitoring, and strengthened regulations to reduce Hg exposure in Indonesia.

Nitrification is one of the most widely used methods to reduce ammonia concentration in wastewater.The purpose of this study was to determine the effectiveness of high-concentrated ammonia nitrification by the consortium between commercial probiotics and bacteria from the sediment of the catfish pond. The study was conducted on batch system bioreactors with a working volume of 1 liter containing 100 mg/L ammonia solution and 50 grams sediment of catfish pond. This study used a treatment variation of the concentration of commercial probiotics and the bacterial isolate from the catfish pond sediment using glucose as the carbon source. The variations of commercial probiotics added to the bioreactor were 5 ml/L, 10 ml/L and 15 ml/L. The variations of glucose concentration were 0 g/L and 3,9 g/L. Analysis of ammonia concentration was carried out by spectrophotometry using the phenate method. The highest removal efficiency of ammonia was 92.35% in the bioreactor with a mixture of 15 ml/L commercial probiotics and 3.9 g/L glucose with the fastest ammonia rate was on the third day of the experimental period. The addition of glucose in the bioreactors could increase ammonia removal by 57.39%. The result of statistical analysis indicated that variations in the concentration of commercial probiotic indicated no statistically significant difference in ammonia removal (P 0.05), while variations in glucose concentration showed a statistically significant difference in ammonia removal (P 0.05). Three isolates were successfully isolated on specific media for nitrifying bacteria. The result of bacterial identification showed that three isolated bacteria were Bacillus sp., Aeromonas salmonicida, and Burkholderia cepacia.Keywords: ammonia, nitrification, sediment of catfish pond, commercial probioticABSTRAKNitrifikasi merupakan salah satu metode yang paling banyak digunakan untuk mengurangi konsentrasi amonia pada limbah cair. Penelitian ini bertujuan untuk mengetahui efektivitas penambahan sedimen kolam lele dan probiotik komersial dalam nitrifikasi amonia konsentrasi tinggi. Penelitian menggunakan bioreaktor sistem batch dengan volume kerja 1 liter yang berisi larutan amonia 100 mg/L dan 50 gram sedimen kolam lele. Perlakuan pada penelitian ini terdiri dari pemberian variasi konsentrasi probiotik komersial dan sedimen kolam lele dengan sumber karbon glukosa. Variasi probiotik komersial yang ditambahkan pada bioreaktor adalah 5 ml/L, 10 ml/L dan 15 ml/L sedangkan variasi konsentrasi glukosa adalah 0 g/L dan 3,9 g/L. Analisis konsentrasi amonia dilakukan secara spektrofotometri menggunakan Metode Fenat. Hasil penurunan rata-rata amonia tertinggi adalah sebesar 92,35% pada bioreaktor dengan campuran probiotik komersial 15 ml/L dan glukosa 3,9 g/L dengan laju penurunan ammonia tercepat pada hari ke-3 periode eksperimen. Penambahan glukosa pada bioreaktor mampu meningkatkan penurunan amonia sebesar 57,39%. Analisis statistik menunjukkan bahwa variasi konsentrasi probiotik komersial tidak menunjukkan perbedaan signifikan pada penurunan amonia (p0,05) sedangkan variasi konsentrasi glukosa menunjukkan perbedaan yang signifikan terhadap penurunan amonia (p0,05). Tiga isolat berhasil diisolasi menggunakan media spesifik bakteri nitrifikasi. Hasil identifikasi dari tiga bakteri menunjukkan bahwa isolat tersebut adalah Bacillus sp., Aeromonas salmonicida dan Burkholderia cepacia.Kata kunci: amonia, nitrifikasi, sedimen kolam lele, probiotik komersial

Tempat pemrosesan akhir (TPA) sampah Galuga merupakan areal controlled landfill untuk sampah domestik penduduk Kota dan Kabupaten Bogor. Areal seluas 54 ha tersebut 92% diperuntukkan bagi sampah domestik Kota Bogor. Sebanyak 500 ton/hari sampah domestik Kota Bogor serta 600 ton/hari sampah domestik Kabupaten Bogor dibuang pada fasilitas penimbusan akhir tersebut. Fasilitas TPA Galuga yang telah beroperasi lebih dari 30 tahun tersebut dilengkapi pula dengan unit proses pengomposan sampah open windrow. Namun laju perolehan produk akhir kompos belum mampu mengimbangi laju penambahan sampah domestik yang masuk ke areal tersebut. Dari sekitar 1100 ton per hari sampah yang masuk ke TPA galuga sekitar 250 – 300 ton per hari sampah yang berupa plastik maupun kertas dapat disisihkan oleh pemulung. Walaupun TPA Galuga merupakan controlled landfill namun belum terkelola dengan baik. Hal tersebut menimbulkan persoalan lingkungan bau sampah serta mutu lindi yang fluktuatif. Terobosan teknologi tampaknya diperlukan untuk menanggulangi persoalan sampah di TPA Galuga. kata kunci : sampah domestik, tempat pemrosesan akhir, penimbusan akhir, kualitas lingkungan

Mercury (Hg) contamination in seafood is a major environmental and public health concern because organic Hg, predominantly methylmercury (MeHg), bioaccumulates and biomagnifies through aquatic food webs. However, information on Hg speciation in fish and seafood from Indonesia remains limited. This study quantified total Hg (THg) and organic Hg (OHg) in 111 specimens representing 15 commercially important fish and seafood species collected from Jakarta Bay, Indonesia, and assessed the associated human health risk. Median THg concentrations ranged from 0.032 to 3.82 mg/kg dry weight (dw), whereas median OHg concentrations ranged from 0.014 to 2.95 mg/kg dw. A comparison with international and Indonesian food safety guidelines showed that Moses perch (Lutjanus russellii) exceeded the maximum permissible Hg concentration, whereas all other species complied with established limits. Median organic Hg accounted for 26.5–89.4% of THg. THg and OHg concentrations were significantly positively correlated with fish length but not weight. Most species presented negligible non-carcinogenic risks (hazard quotient, HQ < 1); however, 16% and 4% of evaluated exposures exceeded the HQ threshold for children and adults, respectively. Overall, Hg speciation combined with human health risk assessment provides a comprehensive evaluation of seafood safety beyond THg alone. These findings provide baseline data supporting consumption advisories, long-term Hg monitoring, and evidence-based risk management in Indonesia.