Problem formulation should seek hypotheses that can be tested in a tiered fashion, because corroboration of hypotheses of no harm when tested with conservative assumptions provides high confidence of low risk. Subsequent tests may refine earlier studies or may progress to studies that are more realistic and complex. These subsequent tests are triggered when the risk assessment requires that more exacting probabilities of exposure and their consequence are needed for decision-making. Since a given tier of testing is only prompted by the risk assessment, the iterative approach effectively focuses consideration to the most relevant concerns and conserves time and resources.
The usefulness of tiered testing and assessment for GM plants is being increasingly recognized (Dutton et al.2003; Garcia-Alonso et al. 2006; Romeis et al. 2008). Published schemes vary in their specifics such as the number of tiers and the nature of tests, but all recognize the critical nature of tiered approaches to iteratively address risk in a manner consistent with the level of concern and the uncertainty in the assessment.
Measurement endpoints
The analysis plan must establish a relevant consequence of exposure consistent with the protection goals articulated in the problem context. This represents measurable effects to an environmental entity of value or its surrogate in response to a changed attribute of the GM plant to which the entity is exposed, where the attribute represents the transgenic protein or some other change of importance. The expression of the measurement endpoint must be consistent with the described route, frequency, duration, and intensity of exposure for the attribute relative to the entity of value.
Most assessment endpoints are not measured directly; instead, other characteristics called measurement endpoints are determined (USEPA 1998). For GM plant ERAs, a measurement endpoint is a measurable response to the changed attribute of the plant that is related to the assessment endpoint. For instance, this may be an acute lethal concentration resulting in the death of 50% of the test organisms (LC50), or a chronic No Observable Adverse Effect Level (NOAEL) measured for the entity of value or its surrogate, or altered fecundity in a receptor population.
Often the analysis plan will also be concerned with measures of system or receptor characteristics. These are characteristics of the ecosystem that influence the behavior and location of entities of value relative to the distribution of the GM plant. For example, life history characteristics may affect the degree of exposure or response to the GM plant. Therefore, the analysis plan may involve determining the abundance and distribution of the entity of value at a relevant life stage within a landscape or region, as in the assessment of Bt maize risk to the monarch butterfly population (Sears et al. 2001).
Risk formulation
The analysis plan will establish the appropriate risk formulation to be considered in the risk characterization. The risk formulation represents the way the exposure measurement is related to the effect measurement. In cases in which the assessment is quantitative, the
การกำหนดปัญหา ควรจะหาสมมติฐานที่สามารถทดสอบในระบบแฟชั่น เพราะการยืนยันสมมติฐานของ ไม่มีอันตราย เมื่อทดสอบกับสมมติฐานที่อนุรักษ์นิยม มีความมั่นใจสูง ความเสี่ยงต่ำ การทดสอบที่ตามมาอาจทำให้การศึกษาก่อนหน้านี้ หรืออาจความคืบหน้าการศึกษาที่สมจริงมากขึ้น และซับซ้อน These subsequent tests are triggered when the risk assessment requires that more exacting probabilities of exposure and their consequence are needed for decision-making. Since a given tier of testing is only prompted by the risk assessment, the iterative approach effectively focuses consideration to the most relevant concerns and conserves time and resources.
ประโยชน์ของระบบการทดสอบและการประเมินสำหรับพืชจีเอ็มจะถูกได้รับการยอมรับมากขึ้น ( ดัตตัน และ al.2003 ; การ์เซียอลอนโซ่ et al . 2006 ; romeis et al . 2008 ) โครงร่างที่แตกต่างกันในรายละเอียดของพวกเขา เช่น จำนวนชั้นและธรรมชาติของการทดสอบ but all recognize the critical nature of tiered approaches to iteratively address risk in a manner consistent with the level of concern and the uncertainty in the assessment.
Measurement endpoints
The analysis plan must establish a relevant consequence of exposure consistent with the protection goals articulated in the problem context.แสดงผลการวัดเป็นหน่วยงานด้านสิ่งแวดล้อมของมูลค่าหรือตัวแทนในการตอบสนองการเปลี่ยนแปลงแอตทริบิวต์ของ ( gmt ) พืชที่นิติบุคคลเป็นสัมผัส ที่เป็นโปรตีนของยีนหรือการเปลี่ยนแปลงอื่น ๆ ที่สําคัญ การแสดงออกของการวัด ( ต้องสอดคล้องกับการอธิบายเส้นทาง , ความถี่ , ระยะเวลา and intensity of exposure for the attribute relative to the entity of value.
Most assessment endpoints are not measured directly; instead, other characteristics called measurement endpoints are determined (USEPA 1998). For GM plant ERAs, a measurement endpoint is a measurable response to the changed attribute of the plant that is related to the assessment endpoint. For instance, this may be an acute lethal concentration resulting in the death of 50% of the test organisms (LC50), or a chronic No Observable Adverse Effect Level (NOAEL) measured for the entity of value or its surrogate, or altered fecundity in a receptor population.
Often the analysis plan will also be concerned with measures of system or receptor characteristics. These are characteristics of the ecosystem that influence the behavior and location of entities of value relative to the distribution of the GM plant. For example, life history characteristics may affect the degree of exposure or response to the GM plant. Therefore, the analysis plan may involve determining the abundance and distribution of the entity of value at a relevant life stage within a landscape or region, as in the assessment of Bt maize risk to the monarch butterfly population (Sears et al. 2001).
Risk formulation
The analysis plan will establish the appropriate risk formulation to be considered in the risk characterization. The risk formulation represents the way the exposure measurement is related to the effect measurement. In cases in which the assessment is quantitative, the
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