Mexican Legislation Research Articles

The effect of reclaimed wastewater on the quality and growth of grapevines

The effect of the use of treated wastewater on the growth of cabernet sauvignon and merlot grapes from the Guadalupe Valley, Mexico was evaluated. Secondary advanced effluent was used to irrigate the grapevines at a rate of 66 L/vine/week. Wastewater quality results confirmed that all parameters complied with Mexican legislation for crop irrigation as well as reuse in activities in which the public would be in direct or indirect contact with the reclaimed water. Results showed that the number of leaves per shoot and the overall biomass increased in plants irrigated with wastewater and grape production per plant was 20% higher. The concentration of carbohydrates, organic acids and pH were similar in grapes from vines irrigated with wastewater to those irrigated with groundwater. Throughout the experiment, no fecal coliform bacteria were detected in the cultivated grapes. The wastewater caused an increase in the biomass of the grapevines and there was no presence of microbial indicators in the final product so a higher wine production could be achieved without an increase in health risk related problems. If 200 L/s of reclaimed wastewater would be returned to be used for grapevine irrigation in Valle de Guadalupe (the same amount that is currently being sent as drinking water to Ensenada), assuming an irrigation application of 6,000-7.500 m3/ha/year, approximately 837-1046 hectares (ha) of grapevines could be irrigated. Part of ongoing research includes an economical analysis of the best options for Ensenada and the Valle de Guadalupe in order to establish the optimum volume of water to be returned, the cost of its transportation, as well as the cost of irrigation.

Environmental legislation and aquatic ecotoxicology in Mexico: Past, present and future scenarios

The consolidation of environmental legislation is fundamental for governments that wish to support and promote different actions focused on reducing pollution and protecting natural water resources in order to maintain the present and future benefits that water provides for human beings and wild life. Environmental laws are essential for sustaining human activities and health, preserving biodiversity and promoting sustainable development. In this context, it is important that environmental regulations concentrate on preventing or reducing the harmful impact of pollutants on organisms and ecosystems. The introduction of toxicity bioassays in environmental regulations is a positive step toward achieving this goal. In Mexico, the development of environmental legislation and the introduction of bioassays in water regulation are part of a very recent and complex journey. This article describes how aquatic ecotoxicology tools, particularly bioassays, have influenced water pollution policies in Mexico. Three scenarios are reviewed: the background of Mexican legislation on water protection and Mexico's participation in the Watertox project; the actual efforts of SEMARNAT to develop bioassay batteries for this country; and, the challenges and perspectives of ecotoxicological bioassays as regulatory instruments.

Oscar J. Polaco, the scientist

The 2006 Fryxell Award for Interdisciplinary Research was granted to Oscar J. Polaco by the Society of American Archeology. A symposium honoring the career and work of the awardee includes this brief presentation of his accomplishments in more than 25 years of research, teaching, and service. His key contributions include 149 scientific publications and the mentoring of over 30 students in subjects as diverse as archeozoology, paleontology, malacology, mammalogy, and acarology; a key role in the development of the Mexican legislation that protects the paleontological resources of the country, as well as an extensive editorial work in all these areas of knowledge.

Sub-soil contamination due to oil spills in six oil-pipeline pumping stations in northern Mexico

Mexico has a very important oil industry, comprehending the exploration, production, transformation, storage and distribution of crude oil and its fractions. Petroleos Mexicanos (PEMEX) is a state-owned monopoly in charge of these activities. Oil and oil-products transport is an extremely crucial operation for the cycle production-transformation-distribution. Pipeline system transport crude oil and sub-products along the country (including liquids, gases and mixtures). It has been reported that more than 30% of the oil ducts in Mexico have been operating for over 30 years, although their lifetime has been calculated in 25-30 years. This work is aimed at characterizing a zone around six oil-pipeline pumping stations located at northern Mexico. The specific places to evaluate soil contamination were (1) the distribution head of the Gomez Palacio (GOPA) pumping station; (2) the north side of the old ditch, the API oil separator and the wastewater zones of the Jimenez (JIM) pumping station; (3) the pumping stations of Ceballos (CE), Peronal (PER), Simon Bolivar (SIBO), and Mayran (MAY). The study comprehended sampling of the areas, delimitation of contamination in the vertical and horizontal extension, analysis of the sampled soils, regarding TPH and, in some cases, the 16 PAHs considered as a priority by USEPA, calculation of areas and volumes contaminated (according to the Mexican legislation, specifically NOM-EM-138-ECOL-2002) and, finally, a proposal for the best remediation techniques suitable for the encountered contamination levels and the localization of contaminants. In general, TPHs were found in all the pumping stations analyzed in this study. Regarding maximal TPHs concentrations at the stations, their order of contamination was as follows: SIBO>CE>PER>MAY>JIM>GOPA. PAHs were found only in a few points at concentrations above the detection limit. At the Jimenez, Gomez Palacio, Peronal, and Ceballos stations, only one point, with PAHs values over the detection limit was found, whereas two points were found at Mayran, and finally at the Simon Bolivar station there were four points with measurable amounts of PAHs. Given the areas and volumes that need to be treated (32835 m3), as well as the physical position of contaminants, it is considered that excavation of the contaminated soil is feasible and the cleaning process could be soil washing assisted with surfactants, though bioremediation should not been discharged as a possible remediation technique.

Sub-soil contamination due to oil spills in zones surrounding oil pipeline-pump stations and oil pipeline right-of-ways in Southwest-Mexico

Oil spills due to oil pipelines is a very frequent problem in Mexico. Petroleos Mexicanos (PEMEX), very concerned with the environmental agenda, has been developing inspection and correction plans for zones around oil pipelines pumping stations and pipeline right-of-way. These stations are located at regular intervals of kilometres along the pipelines. In this study, two sections of an oil pipeline and two pipeline pumping stations zones are characterized in terms of the presence of Total Petroleum Hydrocarbons (TPHs) and Polycyclic Aromatic Hydrocarbons (PAHs). The study comprehends sampling of the areas, delimitation of contamination in the vertical and horizontal extension, analysis of the sampled soils regarding TPHs content and, in some cases, the 16 PAHs considered as priority by USEPA, calculation of areas and volumes contaminated (according to Mexican legislation, specifically NOM-EM-138-ECOL-2002) and, finally, a proposal for the best remediation techniques suitable for the contamination levels and the localization of contaminants.

Exposición involuntaria al humo de tabaco en lugares públicos de la Ciudad de México

Mexican legislation considers many public places as smoke-free spaces. However, no environmental tobacco smoke exposure assessment studies exist to evaluate compliance with governmental regulations and to identify opportunities for tobacco control. The main objective of this study is to quantify airborne nicotine concentrations in public places in Mexico City. During March 2004, nicotine passive monitors were allocated in a hospital, two schools, a public office building, an airport, seven restaurants, and three bars following a common protocol applied in other Latin American countries. Monitors were analyzed at the Johns Hopkins University, extracting the nicotine and quantifying it using nitrogen selective gas chromatography. Median concentrations of environmental nicotine were estimated by type of place and smoking restriction. Airborne nicotine was detected in all public places. The highest concentrations were observed in bars (6.01 microg/m3), restaurants (0.69 microg/m3), airport (0.21 microg/m3), and public offices (0.10 microg/m3). Nicotine exposure concentrations are similar to those previously observed in other capital cities of Latin America. Nicotine levels in the airport and public offices reflect the lack of compliance with mandatory non-smoking official regulations in Mexico. High nicotine concentrations in bars and restaurants provide evidence for the need to advance smoke-free legislative action in these public and work places.

Presence of persistent organochlorine pesticides in estuaries of the subtropical Mexican Pacific

A set of 40 samples of sediments and shrimps (Litopenaeus spp.) from two estuaries in the subtropical Mexican Pacific (San Blas, Nayarit) was analysed to determine the levels of organochlorine pesticides (OCPs). These pesticides have been widely used and dispersed in the study area, either for agriculture crops or control of malaria. For sediments of both estuaries (Pozo-Rey and San Cristobal), the results show that the most frequent compounds were the HCH isomers, endosulphan and DDT group. The shrimp's tissues follow the same pattern of pesticide distribution. The HCH isomers being the most frequent compounds, they demonstrated their broad use. The concentration of OCPs detected in this study area was lower than those previously reported in other wetlands from the Mexican Pacific. All OCPs identified in this work are banned by the Mexican legislation, with their consequent risks to the environment and the public health.

How important is clonal recruitment for population maintenance in rare plant species?: the case of the narrow endemic cactus, Stenocereus eruca, in Baja California, México

Stenocereus eruca is a postrate columnar cactus whose regeneration seems to occur mainly through clonal propagation. It is a narrow endemic species of the Sonoran desert in Baja California Sur and currently considered as threatened under Mexican legislation. In this paper we describe the demography of ramets in four populations along its distribution range and the demography of genets in one population during a 3-year-study period in order to evaluate its conservation status. We also analyze the relative contribution of sexual reproduction and clonal propagation to population maintenance and provide guidelines for the formulation of conservation programs. Elasticity analyses were used to explore the relative contribution of sexual and clonal recruitment to projected population growth rate ( λ). During the three years of study, regeneration occurred only through clonal propagation while sexually derived seedlings were not detected within or outside the permanent plots. Our demographic data showed that the four population of S. eruca are in equilibrium ( λ ≈ 1), and elasticity analyses showed that the relative contribution to λ of clonal recruitment was larger than sexual recruitment, at least during the analyzed ecological time scale. Simulations showed that removing sexual recruitment had a minor impact on λ, but the absence of clonal propagation alone was sufficient to keep below unity. We propose the establishment of at least one reserve with adequate protection from human disturbance to conserve S. eruca.

Las infracciones tributarias en el sistema tributario mexicano

Numero 114 Septiembre - Diciembre 2005 Nueva Serie Ano XXXVIII ISSN 0041 8633 LAS INFRACCIONES TRIBUTARIAS EN EL SISTEMA TRIBUTARIO MEXICANO Gabriela RIOS GRANADOS * One of citizens´ most fundamental duties is to pay taxes, with the purpose of providing the government with sufficient resources to satisfy the demand for public services. Tax fines imposed by tax authorities, caused by the infringement of tax laws, is one of several means to dissuade unlawful behavior on behalf of taxpayers, which could negatively affect the public interest. In this essay, the author studies tax fines, discussing their juridical nature and analyzing the contents of Mexican legislation related to this topic, such as the Federal Fiscal Code and customs legislation. Descriptors: taxes, administrative sanctions, administrative law. * Investigadora del Instituto de Investigaciones Juridicas de la UNAM. * Nota: Debido que la traduccion es automatica podra ser inexacta o contener errores.

Quality assessment of reclaimed water for its possible use for crop irrigation and aquifer recharge in Ensenada, Baja California, Mexico

The city of Ensenada, Baja California, has three wastewater treatment plants and is one of the few cities in Mexico that treats all the wastewater that it generates. The largest wastewater treatment plant, called El Naranjo, treats on average 316 liters per second and complies with even the most stringent Mexican standards although a stricter control has to be achieved in order to avoid environmental and health problems At the moment, only 2% of the treated wastewater is used for the irrigation of sports fields and public landscape. The reclaimed water could be reused for the irrigation of crops for non-human consumption or ornamental products and/or for aquifer recharge. For reuse practices, two facts must be considered: a) an important part of the valley's production is exported to the USA and b) 30% of the city of Ensenada's water supply is obtained from the Maneadero aquifer. There is currently no Mexican legislation to stipulate adequate standards for aquifer recharge and decisions should be based on legislation from other places. Therefore, at the moment there is still a lack of technical and scientific elements to be able to make the best decision about the reuse of the wastewater.

Remediation of contaminated soil using soil washing and biopile methodologies at a field level

An out-of-service oil distribution and storage station (ODSS), which operated from 1966 to 2000 in Mexico, is contaminated mainly by gasoline and diesel, showing the presence of methyl-tert-butyl-ether, benzene, toluene, ethyl benzene, and xylenes. Nine of the 16 polycyclic aromatic hydrocarbons were found, as well as Fe, Pb, V, and Zn. The health risk assessment suggested the necessity of reducing of three PAHs [benzo(a)anthracene, benzo(a)pyrene, and benzo-(b)fluoranthene], and vanadium. The aim of this work is to show that soil washing (on-site) and biopiles are excellent remediation methodologies to treat soils contaminated with petroleum derivates and metals. Applying them, it is possible to reach the goal value of 2,000 mg TPH/kg in a few months, as requested by Mexican legislation. More than 140 m3 were excavated from the ODSS. Three soil-washing dishes were built. 1540 m3 were treated by soil washing using a nonionic surfactant. A 100 m3 biopile was built to study the system capabilities in the biodegradation of around 4,500 mg/kg of TPH using the autochthonous microflora. The soil washing, average TPH-removal value was 83%, but values up to ca. 93% were observed. Removal values resulted in a function of the TPH initial values. Biopile (100 m3) worked during 66 days, reaching a TPH-removal value of 85%. At the end of the processes, no PAHs were detected. The contaminated soil was treated successfully, reaching the legislation limits (TPH values under 2,000 mg/kg, and a significant reduction in PAH concentrations). Both systems are suitable for remediation purposes, achieving high removal efficiencies at short and medium stages. It is highly recommended to proceed with soil washing studies, identifying new products, and mixtures, which could reduce costs and assure optimum operation.

Performance of basaltic dust issued from an asphaltic plant as a flocculant additive for wastewater treatment

The feasibility of using basaltic dust as a flocculant additive or coagulant aid for wastewater treatment was assessed in this research. The experimental study was divided into two stages: 1) physicochemical characterisation of the basaltic dust by applying standardised techniques, and 2) evaluation of this material as flocculant additive for the coagulation-flocculation of wastewater treated for reuse. Coagulation-flocculation experiments were carried out in the laboratory with a mixture of industrial and municipal wastewater samples collected from two points of the final discharge of the Mexico City sewerage system. Aluminium sulphate and lime were used as coagulants and the basaltic dust as flocculant additive, by applying the jar-test technique. The results of the corrosivity, reactivity, explosiveness, toxicity, inflammability and biological risk tests indicated that this material is classified as a non-hazardous waste (according to the Mexican legislation, NOM-052-ECOL-1993). The density, oxide content and particle size values of basaltic dust were similar to those reported for the flocculant additive denominated activated silica. The jar test results showed a positive effect of basaltic dust over the effluent and sludge qualities, to the extent that coagulant doses can be reduced 30% (from 150 mg/L to 110 mg/L of Al2(SO4)3).

Evaluation of the UV disinfection process in bacteria and amphizoic amoebae inactivation

Every year around 3.4 million people die from water-related diseases, mainly amoebiasis and diarrhoea caused by bacteria. The assessment of the efficiency of a UV light disinfection process in the inactivation of indicators, pathogen bacteria and amphizoic amoebae in a secondary treated effluent was carried out. Wastewater was irradiated with different doses of UV light using a collimated-beam reactor. Dose-response results showed that a UV dose of 15 mW·s/cm2 was enough to inactivate FC to the limit established in Mexican legislation (<1,000 MPN/100 ml) for irrigation reuse, as well as reaching a 2 log inactivation for faecal streptococci. Also, the final concentration reached for Salmonella typhi was <103 MPN, which is the minimal concentration for a disease response in humans. The isolation from the secondary effluent and the pathogenicity determination of Acanthamoeba were carried out. Amoebae were concentrated to higher concentrations than those of the effluent for irradiation tests. Radiation tests showed that amoebae required higher doses than bacteria for their total inactivation (60 mW·s/cm2 for a 2 log reduction). Results showed that UV light is an alternative to inactivate high contents of bacteria and amoebae trophozoites, although higher doses were needed for the high concentrations of amoebae used.

Getting incentives right?: a comparative analysis of policy instruments for livestock waste pollution abatement in Yucatán, Mexico

Building on the extensive theoretical and empirical work regarding the cost-minimizing properties of economic instruments, this article describes and analyses the Mexican legislation relevant to the treatment/disposal of pig slurry in the state of Yucatán. Using a linear programming model to determine the optimal level of pig production and abatement processes simultaneously, different policy instruments and scenarios are compared. Serious shortcomings associated with the recently introduced command-and-control (CAC) legislation, which establishes concentration-based standards for discharges, are identified. It is shown that it will be extremely difficult and expensive to comply with (cost: US$41.8 million per annum). An alternative mass-based CAC approach, which instead regulates nitrogen applications to land, has compliance costs of US$3.5–US$9.4 million per annum, depending on the strictness of the standard. By contrast, an environmentally equivalent economic instrument approach results in additional cost savings of 22–25 per cent. The results are of relevance to Mexican policy makers, extensionists, researchers, and farmers.

Solid waste management in municipalities in Mexico: goals and perspectives

Mexico is faced with serious environmental and administrative challenges with respect to solid waste (SW) management. Just as in other developing countries, the public sanitation system lacks because of inadequate planning, as well as unsustainable SW management. The country is experiencing an urbanization process in which approximately 70% of the population are concentrated in its ten largest cities; the rest are spread throughout 200 000 towns in Mexico's 2 000 000 km 2. This has caused a change in the population's consumption patterns, which has resulted in a more heterogeneous composition of SW and an increase in its generation rate. The current situation of the SW management systems in Mexico is analyzed, and the environmental, technical, administrative, economic and social goals with which Mexico's public sanitation systems face, are discussed. The principal goal facing these public sanitation systems is the development of adequate disposal of SW, since the municipalities find themselves unable to administer sanitary landfills according to Mexican legislation because they lack financial means and the technical and human infrastructure. SW collection in Mexico depends heavily on personnel with no technical training and the separation of the waste is carried out by an ever-increasing number of scavengers. The importance of including these groups in the decision-making process in order to assure the success of SW management programs is presented, along with the need to create interdisciplinary work groups that could collaborate in driving forward the agenda.

Characterisation and conditioning of Fenton sludges issued from wastewater treatment

Characterisation tests were conducted to determine the feasibility of land application of the sludges produced in wastewater treatment by means of Fenton's Reagent. Physicochemical and microbiological parameters of Fenton sludges were compared to the values obtained for raw alum sludges. The Fenton sludges presented preferable characteristics such as the specific resistance to filtration (SRF), metals and pathogen content (fecal and tot al coliforms, helminth ova, and Salmonella sp.). The SRF ofthe Fenton sludges (1.55 x 10(13) m/kg) was 24% less than the alum sludge value (1.92 x 10(13) m/kg). The concentrations of fecal coliforms (0 MPN/g TS), Salmonella sp. (0 MPN/g TS), Helminth ova (22 HH/g TS) and metals correspond to the limits for biosolids of Class B for land application of the Mexican legislation. The Fenton reagent efficiently removes most of the pathogens, considered by the norms, by means of the combined action of the different stages that constitute this process. These results exhibit the Fenton reagent as a feasible treatment for generating sludges with characteristics of biosolids of Class B for land application. The preliminary results of conditioning tests show that Fenton sludges present better dewatering characteristics with regard to the alum sludge, for a dose of cationic polymer of 1 mg/g TS.

Rediscovery of Pedilanthus coalcomanensis (Euphorbiaceae), a threatened endemic Mexican species

Pedilanthus coalcomanensis was described from specimens collected by George B. Hinton in 1941 but was not collected again until 1999, when we found it in a tropical deciduous forest near Tehuantepec, in Chinicuila, Michoacán, Mexico. After analyzing Hinton's original collection notes, we concluded that this is the type locality. Based on the reduced geographic distribution presently known for this species (11 km(2)), the level of disturbance of its habitat, and the use of the method for the assessment of extinction risk in Mexican wild species (MER), we propose that P. coalcomanensis be covered by the appropriate Mexican legislation as a threatened species and be included in the Red List of Threatened Plants of the International Union for the Conservation of Nature. Our results help justify and delimit a local biosphere reserve in northwestern Michoacán, an area that is considered a center of endemism and that has largely been deforested. Our findings have implications for research on other historical specimens collected by Hinton in this region.

Management plans for natural protected areas in Mexico: La Sierra de la Laguna case study

Summary Mexican Natural Protected Areas main goals are to protect biodiversity in the core areas and to achieve sustainable development of natural resources in their influence zone. According to Mexican legislation, all newly established biosphere reserves must have a Management Plan (MP). This MP must regulate all activities in the area, and guarantee that the short-and long-term objectives of the reserve will be achieved satisfactorily. In this paper, we outline the required information and topics to be included in all MPs. We describe the main recommendations offered in the MP for a new Natural Protected Area in Mexico: the La Sierra de la Laguna Biosphere Reserve. The document provides the Federal authorities with all the basic information, scientificallysupported, for sustainable management of the natural resources of the reserve. The main goal of this MP was to promote the sustainable socioeconomic development of the region, its resources, and its inhabitants.The information provided should be useful to compare with other countries the differences and similarities in official guidelines of MPs, to enhance sustainable use of resources in Natural Protected Areas.

Effects of organic material and distribution of fecal coliforms in Chetumal Bay, Quintana Roo, México

Most wastewater from the city of Chetumal is discharged into the adjoining bay without treatment through a pluvial sewer system. The bay also receives a high volume of vegetal organic material from the River Rio Hondo. The average of biochemical oxygen demand (BOD) was 32.26 mg l-1, it was low compared with other reports and should be indicative of self-depuration processes in Chetumal Bay. In the area most used by the public for recreational and fishing activities, concentrations of fecal coliforms above the limit established by Mexican Legislation were shown. The border between Mexico and Belize is Chetumal Bay, which recently was declared a protected area for manatees.

The New Mexican Legislation on Commercial Arbitration

The New Mexican Legislation on Commercial Arbitration