Environmental mercury pollution in ; Xolotlán Lake a case of pollution.

Francisco J. Picado Pavón Research Center for Aquatic Resources of Nicaragua National Autonomous University of Nicaragua [email protected] Nicaragua main Volcanoes

Cosigüina (1859) San Cristóbal (2012) (2015) (1999) El Hoyo (2015)

Apoyeque Masaya (Continuing) Apoyo (1570) Zapatera

Concepción (2009) 1980-2000 (20 year) Worldwide flux of Hg from volcanic eruptions Total global flux of Hg is ̴ 57.0 t/year to the atmosphere is ̴ 112 t/year Worldwide flux of Hg from degassing activities (Nriagu and Becker, 2003) is 37.6 t/year

Regional average of Volcanic Hg emissions (t/year) between 1980 and 2000

Worldwide South and Southeast Asia North America + Hawaii Australia Japan +northern Asia Europe and western Asia (Nriagu and Becker, 2003) Africa

0 20406080100 Volcanic Hg emissions (t) between 1980‐2000

The Hg emissions from Nicaraguans volcanoes accounts for 25% of worldwide Hg volcanic Cosigüina emissions (Nriagu and Becker, 2003) San Cristóbal (0.472) Telica (0.144) • Hg concentrations in the plume Cerro Negro (0.015) were above background and 3 El Hoyo Momotombo (0.010) ranged up to 350 ng/m • TGM concentrations range from 100 to 225 ng/m3 Apoyeque • RGM accounted for 1% of TGM, and TPM is ̴ 5% of the TGM Masaya (22.7) • Hg flux from Masaya of 7.2 Apoyo t/year) (Witt et al, 2008; Mombacho University of Oxford, 2008, June Zapatera 30)

Concepción Maderas Anthropogenic Hg emissions to the atmosphere 2010 (AMAP/UNEP, 2013)

0,05%

Xolotlán Lake a case of pollution Objective

To assess the current Hg concentrations in Xolotlán Lake for continue benefiting from its hydrobiological resources. Before laboratory improvement

Nicaragua government aims for strengthening capacities for Hg analysis After created the conditions and equipped the laboratory Economic support of the Japanese government through the Japan International Cooperation Agency (JICA) and the Nicaraguan counterpart Strengthening capacities for Hg analysis at NIMD, Japan

Strengthening capacities for Hg analysis at EML, Nicaragua Sampling (water, sediment and fish) Sampled sites at Xolotlán Lake, 2016. Februray, 2016 June, 2016 September 2016 – February, 2017 San Fco Libre (Chlor Alkali production facility) Laboratory analyses DTHg and PTHg (water) THg (sediments) THg (fish)

Quality Control Assurance Duplicates Blanks La Bocana Cotrol Samples de Tipitapa CRMs Inter laboratory comparison Guidelines Canadian Environmental Quality Chlor Alkali production facility Guidelines for (water and sediment) International (fish) Collected samples at Xolotán Lake First Second Sediment sampling sampling sampling at polluted site (Feb.2016) (Jun.2016) (Dic.2016-Feb.2017) Surface water 35 34 ‐‐‐ Depth water 18 18 ‐‐‐ Surface sediment 11 14 72

Guapotes (146) Mojarras (215) Guabinas (194) Tilapias (74)

Quality Control Assurance

February 2016 Water Sediment (ppm) Fish (ppt) (ppm) Certified BCR579 IAEA‐158 DORM II Values→ (1,9 ±0,5) (0,132 ± 0,014) (4,64 ± 0,26) ( Laboratory Results→ 1,85 ±0,40 0,132 ± 0,007 4, 78 ±0,04 ( Laboratorio de Mecurio Ambiental, CIRA/UNAN‐Managua. 2016

June 2016 Water Sediment Fish (ppt) (ppm) (ppm) Certified Values→ BCR579 IAEA‐158 DORM II ( (1,9 ±0,5) (0,132 ± 0,014) (4,64 ± 0,26) Laboratory Results→ 2,28 ±0,13 0,131 ± 0,009 4, 72 ±0,09 ( Laboratorio de Mecurio Ambiental, CIRA/UNAN‐Managua. 2016

No statistic difference (p=0.52, α=0.05) of the total dissolved Hg concentrations was observed between sampling campaigns, but significant difference (p = 0.03, α = 0.05) was observed in the values of concentration of particulate Hg.

The few data of Hg concentrations exceeding the Canadian values for aquatic life protection (water=26.0 ng/l, sediment=0.17 μg/g) were observed close to anthropogenic or natural Hg sources. Recognition Sampling for Sediment at most polluted area of Xolotlán Lake. September 2016. THg (mg/kg)

14.69 16.68 13.62 20.1 5.37 0.85 0.87 0.78 1.06 1.06 1.23 0.92 Protection of aquatic life CEQGs Sediment (ppm) = 0,17 Protection of aquatic life CEQGs Sediment (ppm) = 0,17

Total Hg concentrations (mg/kg) in surface sediments from polluted site of Xoltlán Lake (Chlor Alkali production facility), December 2016. Total mercury concentration (ppm) in four especies of edible fish from Xolotlán Lake

THg concentration (mg/kg wet wt.) Fish from two fishing villages All fish San Francisco Libre La Bocana de Tipitapa

Fish n Min. Max. Prom n Min. Max. Prom n Min. Max. Prom Guapotes 146 0,109 1,020 0,465 109 0,109 1,020 0,473 37 0,175 0,897 0,442 Mojarras 215 0,008 0,658 0,251 101 0,013 0,620 0,299 114 0,008 0,658 0,209 Guabinas 194 0,080 0,454 0,230 101 0,121 0,454 0,248 93 0,080 0,427 0,209 Tilapias 74

Amphilophus citrinellus (0.25 μg/g) > Gobiomorus dormitor (0.23 μg/g) > Oreochromis niloticus, Oreochromis mossambicu, Oreochromis aureus (0.02 μg/g)

19.1% of all four studied species is above 0.40 μg/g, the recommended concentration for fish consumption in Japan.

Total Hg concentration (mg/kg wet wt.) in four edible fish from Xolotlán Lake. 2016 Conclusions

The low bioavailable mercury aqueous concentrations suggest that fish Hg intake occurs mainly through food chain.

Sediments are an important source of mercury for aquatic food chain in Xolotlán Lake.

Current Hg content in edible fish indicates a bioaccumulation that in the future could increase and consequently turn a threat whether people increase the consumption of these fish.

A multimedia Hg monitoring, including Hg speciation, of Xolotlán Lake is needed. References

• Jerome Nriagu and Christian Becker, 2003. Volcanic emissions of mercury to the atmosphere: global and regional inventories. The Science of the Total Environment. 2003: 304: 3–12. • AMAP/UNEP, 2013, Technical Background Report for the Global Mercury Assessment 2013, Arctic Monitoring and Assessment Programme, Oslo, Norway/UNEP Chemicals. • University of Oxford. (2008, June 30). Volcano 'Pollution' Solves Mercury Mystery. ScienceDaily. Retrieved September 17, 2018 from www.sciencedaily.com/releases/2008/06/080629081932.htm • Witt, M. L. I., T. A. Mather, D. M. Pyle, A. Aiuppa, E. Bagnato, and V. I. Tsanev (2008), Mercury and halogen emissions from Masaya and Telica volcanoes, Nicaragua, J. Geophys. Res., 113, B06203, doi:10.1029/2007JB005401. • Reporte técnico: Estado actual de la contaminación por Mercurio del Lago Xolotlán y evaluación de riesgos para la salud de los habitantes por la exposición al Mercurio. Proyecto para el fortalecimiento de capacidades en el estudio y análisis de Mercurio en la república de Nicaragua, Agosto, 2017.